How to Optimize Videos for YouTube Search

How does YouTube search engine marketing work? What are the steps to optimize your YouTube movies for search? The solutions to those questions are easier than you would possibly assume.

Whereas it may appear troublesome to get any publicity on YouTube, you possibly can implement sure methods to make sure that the YouTube algorithm favors you within the search outcomes.

On this submit, we’ll go over confirmed YouTube search engine marketing suggestions which have labored for HubSpot’s YouTube channel and that may be just right for you, no matter your channel measurement. Let’s get began.

Tips on how to Rank Movies on YouTube

To get movies to rank on YouTube, we should first perceive the YouTube algorithm and YouTube’s rating elements.

Identical to any search engine, YouTube desires to ship content material that solutions the searcher’s particular question. For example, if somebody searches for “find out how to tie a tie,” YouTube gained’t ship a video titled “find out how to tie your shoelaces.” As a substitute, it’s going to serve search outcomes that reply that particular question.

So, as you attempt your hand at YouTube search engine marketing, take into consideration how one can incorporate phrases and phrases which might be utilized by your audience.

You’ll additionally want to consider YouTube analytics and engagement. When it ranks movies, YouTube cares a few metric known as “watch time” — in different phrases, how lengthy viewers keep in your video. An extended watch time implies that you’re delivering worthwhile content material; a brief watch time implies that your content material ought to doubtless not rank.

If you’d like your movies to rank, attempt to create content material that’s optimized for longer watch occasions. You possibly can, for example, immediate customers to remain till the top of the video by promising a shock or a giveaway.

Is it value optimizing movies on YouTube?

Attempting to rank movies on YouTube would possibly seem to be a misplaced effort. Solely probably the most well-known influencers and content material creators appear to have any luck on the platform.

Nonetheless, that’s not the case. As a enterprise, you possibly can get pleasure from views, feedback, and likes in your movies — as long as you discover the correct viewers on your content material. In truth, discovering and focusing on the correct viewers is much more necessary than making a “stunning” video. In the event you’re actively fixing your potential clients’ issues together with your YouTube movies, you then’ve achieved 90% of the YouTube optimization work.

As well as, rating movies on YouTube is a key factor of your inbound advertising technique, even when it may not appear that method. As not too long ago as a decade in the past, inbound video advertising was a model new concept. Entrepreneurs had been studying that they could not simply publish a excessive quantity of content material — it additionally needed to be high-quality and optimized in ways in which made it as discoverable as potential by means of serps.

That content material was as soon as largely restricted to the written phrase. At present, that is now not the case. As a substitute, a complete content material technique consists of written work like blogs and ebooks, in addition to media like podcasts, visible property, and movies. And with the rise of different content material codecs comes the necessity to optimize them for search. One more and more necessary place to try this is on YouTube.

In the event you’re feeling misplaced, don’t fear. We cowl crucial YouTube search engine marketing suggestions and technique under so you possibly can successfully optimize your content material for YouTube search.

YouTube search engine marketing combines primary search engine marketing practices with YouTube-specific optimization strategies. In the event you’re new to SEO, take a look at this whole search engine marketing information.

YouTube Technique

To achieve success on YouTube, you will want a transparent technique. This technique has two elements. First, you want to perceive how YouTube search engine marketing works. Then, you will wish to use that information as you select a audience, develop a plan on your channel, and set targets for development.

How YouTube search engine marketing Works

YouTube is a part of Google and it makes use of related search algorithms to point out customers the movies that finest match their search queries.

This algorithm makes use of totally different parts in every video submit to resolve how that video will rank for particular search phrases. These parts embrace:

• Video title
• Video description
• Metadata
• Variety of views, feedback, and likes
• Watch time

The algorithm additionally considers the previous exercise of the one that is looking out. This helps search outcomes really feel extra personalised to that consumer.

When mixed, these indicators inform the algorithm how related, fashionable, or participating your video submit is for a consumer’s question.

Select a Goal Viewers

For a lot of content material creators, viewers development begins with selecting a subject, then optimizing YouTube movies. However with development comes competitors. It was as soon as easy to create a YouTube channel for a broad subject like product evaluations or tech, however right this moment new YouTube channels want a extra particular focus.

As you slender your audience, take into consideration who you wish to interact together with your channel and why. Ask your self:

• How a lot are you aware about your audience?
• Why do they spend time on YouTube?
• What different social media platforms does your viewers choose?
• What conjures up their curiosity and loyalty?
• Are there different YouTube channels or creators that it’s best to companion with to attach with this viewers?

Develop a Plan

Making a content material plan can appear easy in case your YouTube channel facilities on a subject you like. However more often than not, the problem is not in arising with concepts, it is about making them occur.

If you wish to optimize YouTube for search engine marketing, content material planning is not nearly what movies you make and when to submit them. It is a course of to determine what sources you want to enhance site visitors, conversion, and engagement together with your video content material.

For instance, you’ll have a fantastic concept for a video about browsing, however the place are you getting your footage? In the event you’re not recording your self or your area people, it could be powerful to search out high-quality supply materials on your movies.

Constructing skilled abilities or a workforce with experience in modifying, sound, and animation may also increase the standard of your movies. But when these sources aren’t available to you, it’s possible you’ll want a plan to create nice movies with out them.

Aggressive evaluation may also assist with planning, whether or not you are determining the correct video size or the place to advertise your movies on different social platforms.

This free content material planning template might help you create a strong plan on your YouTube technique.

Featured Useful resource: Content material Planning Templates

Set Objectives for Progress

YouTube affords many useful metrics that may enable you to assess whether or not your workforce is assembly your strategic targets. Broad metrics may be useful to trace consistency and large shifts in efficiency, like algorithm modifications.

However it’s additionally a good suggestion to decide on centered metrics that align together with your targets. For instance, if you wish to enhance your viewers, observe your subscriber rely, impressions, and viewers retention. If engagement is your objective, have a look at likes, feedback, shares, and watch time. Driving internet site visitors? Add hyperlinks to your video descriptions and annotations, then observe these sources in your web site.

Monitoring the metrics that align together with your targets will enable you to find out how you are rising your viewers. You need to use that information to create simpler movies on your customers and search engine marketing. And that effort will enable you to continue to grow your YouTube channel.

1. Rename your video file utilizing a goal key phrase.

Identical to you’ll when optimizing written content material, you will use an search engine marketing software to first determine key phrases you need your video to concentrate on (you possibly can browse fashionable YouTube search engine marketing instruments later on this submit, or simply click on this hyperlink).

With a key phrase recognized, the primary place to place it’s your video file — earlier than you even add it to YouTube. Why? YouTube cannot truly “watch” your video to see how related it’s to your goal key phrase, and as you will be taught within the suggestions under, there are solely so many locations you possibly can safely insert this key phrase in your video’s viewing web page as soon as it is printed. However, YouTube can learn your video’s file title and all of the code that comes with it when it is uploaded.

With that in thoughts, change the “business_ad_003FINAL.mov” file title (do not be embarrassed — we have all been there throughout post-production) together with your desired key phrase. In case your key phrase is “home portray suggestions,” for instance, your video’s file title must be “house-painting-tips” adopted by your most well-liked video file kind (MOV, MP4, and WMV are a number of the commonest which might be appropriate with YouTube).

2. Insert your key phrase naturally within the video title.

While you seek for movies, one of many first issues that your eyes are drawn to is the title. That is usually what decides whether or not you will click on to observe your video, so the title shouldn’t solely be compelling, but additionally clear and concise.

Though your key phrase performs an enormous half in your video title, it additionally helps if the title intently matches what the viewer is looking for.

It is a good suggestion to optimize your title for key phrases as long as the key phrase suits naturally right into a title that tells viewers precisely what they’re about to see.

Lastly, ensure that to maintain your title pretty quick — HubSpot campaigns supervisor Alicia Collins recommends limiting it to 60 characters to assist preserve it from getting minimize off in outcomes pages.

3. Optimize your video description.

First issues first: Based on Google, the official character restrict for YouTube video descriptions is 1,000 characters. And whereas it is okay to make use of all that house, keep in mind that your viewer probably got here right here to observe a video, to not learn an essay.

In the event you do select to put in writing an extended description, take into account that YouTube solely shows the primary two or three strains of textual content — that quantities to about 100 characters. After that time, viewers need to click on “present extra” to see the complete description. That is why we recommend front-loading the outline with crucial data, like CTAs or essential hyperlinks.

As for optimizing the video itself, it’s good so as to add a transcript of the video, particularly for individuals who have to observe it with out quantity.

An optimized description may also enable you to present up within the prompt movies sidebar, which is usually a nice supply of views.

In the event you want a high-performing video description, attempt certainly one of these confirmed YouTube description templates.

Obtain These Templates for Free

4. Tag your video with fashionable key phrases that relate to your subject.

YouTube suggests utilizing tags to let viewers know what your video is about. However you are not simply informing your viewers — you are additionally informing YouTube itself. YouTube makes use of tags to know the content material and context of your video.

That method, YouTube figures out find out how to affiliate your video with related movies, which might broaden your content material’s attain. However select your tags correctly. Do not use an irrelevant tag since you assume it will get you extra views — actually, Google would possibly penalize you for that. And like your description, lead with crucial key phrases, together with an excellent mixture of these which might be frequent and extra long-tail (as in, people who reply a query like “how do I?”).

Use these easy directions so as to add and benefit from tags in your YouTube movies.

5. Categorize your video.

When you add a video, you possibly can categorize it below “Superior settings.” Selecting a class is one other solution to group your video with related content material on YouTube so it winds up in several playlists and good points publicity to extra viewers who determine together with your viewers.

It may not be so simple as it appears. In truth, it is necessary to undergo a complete course of to search out which class every video belongs in. Reply questions like:

• Who’re the highest creators inside the class? What are they identified for and what do they do effectively?
• Are there any patterns between the audiences of comparable channels inside a given class?
• Do the movies inside an analogous class share qualities like manufacturing worth, size, or format?

6. Add a customized thumbnail picture on your video’s consequence hyperlink.

Your video thumbnail is the primary picture viewers see when scrolling by means of an inventory of video outcomes. Together with the video’s title, that thumbnail sends a sign to the viewer concerning the video’s content material, so it might probably influence the variety of clicks and views your video receives.

When you can at all times choose one of many thumbnail choices auto-generated by YouTube, we extremely suggest importing a customized thumbnail. YouTube recommends utilizing photos which might be 1280×720 pixels — representing a 16:9 ratio — which might be saved as 2MB or smaller .jpg, .gif, .bmp, or .png information. In the event you observe these parameters, it might probably assist to substantiate that your thumbnail seems with equally prime quality throughout a number of viewing platforms.

It is necessary to notice that your YouTube account must be verified to add a customized thumbnail picture. To try this, go to youtube.com/confirm and observe the directions listed there.

7. Use an SRT File so as to add subtitles & closed captions.

Like a lot of the opposite textual content we have mentioned right here, subtitles and closed captions can increase YouTube search optimization by highlighting necessary key phrases.

So as to add subtitles or closed captions to your video, you will need to add a supported textual content transcript or timed subtitles file. For the previous, you may as well instantly enter transcript textual content for a video in order that it auto-syncs with the video.

Including subtitles follows an analogous course of, however you possibly can restrict the quantity of textual content you need displayed. For both, head to your video supervisor then click on on “Movies” below “Video Supervisor.” Discover the video you wish to add subtitles or closed captioning to, and click on the drop-down arrow subsequent to the edit button. Then, select “Subtitles/CC.” You possibly can then select how you need so as to add subtitles or closed captioning.

Learn how so as to add closed captions to your YouTube video within the video under.

8. Add Playing cards and Finish Screens to extend your YouTube channel’s viewership.

Playing cards

While you’re watching a video, have you ever ever seen a small white, round icon with an “i” within the middle seem within the nook, or a translucent bar of textual content asking you to subscribe? These are Playing cards, which YouTube describes as “preformatted notifications that seem on desktop and cell which you’ll set as much as promote your model and different movies in your channel.”

Picture Supply

You possibly can add as much as 5 playing cards to a single video, and there are six varieties:

1. Channel playing cards that direct viewers to a different channel.
2. Donation playing cards to encourage fundraising on behalf of U.S. nonprofit organizations.
3. Fan funding to ask your viewers to assist assist the creation of your video content material.
4. Hyperlink playing cards, which direct viewers to an exterior web site, authorized crowdfunding platform, or an authorized merchandise promoting platform.
5. Ballot playing cards, which pose a query to viewers and permit them to vote for a response.
6. Video or playlist playing cards, which hyperlink to different YouTube content material of this sort.

For detailed steps on including a card to your video, observe these official steps from Google, or take a look at the video under.

Finish Screens

Finish screens show related data as playing cards, however as you’ll have guessed, they do not show till a video is over and are a bit extra visually detailed in nature. An excellent instance is the overlay with a e-book picture and a visible hyperlink to view extra on the video under:

Picture Supply

There are a selection of detailed directions for including finish screens relying on what sort of platform you wish to design them for, in addition to various kinds of content material allowed for them by YouTube. Google outlines the main points for find out how to optimize for these concerns right here.

It is necessary to notice that YouTube is at all times testing finish screens to attempt to optimize the viewer expertise, so there are occasions when “your finish display screen, as designated by you, might not seem.” Take these elements into consideration as you resolve between utilizing both playing cards or finish screens.

These elements could appear a bit difficult and time-consuming, however bear in mind: The time individuals spend watching YouTube on their TV has greater than doubled yr over yr. There’s an viewers to be found there, and while you optimize for YouTube, your probabilities of being found enhance.

9. Add hashtags to extend attain.

Hashtags are part of the YouTube consumer interface that permit you to add associated phrases to your content material, simply as you’ll on LinkedIn or Instagram. Hashtags present up proper above your video title for simple clicking and discoverability. You need to use your organization title, as HubSpot does under, or embrace associated key phrases.

We additionally suggest utilizing hashtags in your YouTube description, however don’t go overboard; the YouTube algorithm always checks for spam. Overly hashtagging might get you inadvertently flagged. As a substitute of utilizing each hashtag you possibly can consider, select 2-3 that you just really feel most precisely describe your video.

10. Create a playlist about your video’s basic subject.

As you add increasingly more movies to your content material library, group them in keyword-optimized playlists. This gained’t solely sign to YouTube what your movies are about, however it’s going to additionally preserve viewers clicking from video to video, growing your view rely and, by extension, your rankings.

For instance, Yoga with Kassandra grouped all of its quick yoga lessons in a playlist titled “5-15 min Yoga Courses.” Not solely is the title quick and descriptive, however the playlist description consists of associated key phrases comparable to “10 minute yoga lessons,” “10 minute morning yoga stretches,” and “bedtime yoga lessons.”

11. Experiment with video size.

The extra time viewers spend watching movies in your channel, the higher it’s on your search engine marketing. However not each particular person on YouTube will stick round for 10 minutes or extra.

For instance, over 70% of watch time on YouTube occurs on cell gadgets. Whereas some individuals can watch an hour-long video on a small display screen, this determine reveals how necessary it’s to know your viewers.

To search out the correct watch time on your viewers, attempt creating movies of various lengths. Then, do a fast evaluation of the watch time, common view period, and viewers retention for every video and modify your technique.

12. Use YouTube’s autocomplete function.

This function makes it easy to search out the preferred search phrases on your video subject. Simply begin typing a key phrase phrase and see what different key phrases and phrases come up. Then, add probably the most related phrases to your title, descriptions, and tags.

You may also use this software to find prime YouTube tendencies or to determine which key phrases your rivals are focusing on. These insights might help you pivot your YouTube search engine marketing technique for higher outcomes.

Take a look at this submit for extra helpful YouTube options.

13. Attempt timestamps.

Timestamps mark totally different sections of your movies. They make it straightforward on your viewers to search out the content material they’re on the lookout for inside every video.

Including a timestamp can enhance retention and consumer expertise as a result of it units expectations. Timestamps give watchers a simple solution to bounce to what they wish to see in a video or a purpose to attend for that part to seem on-screen.

Timestamps additionally enhance search engine marketing as a result of they make it simpler for YouTube’s algorithm to know your video content material. This helps your video seem for search phrases inside your video, not simply the general theme of your video.

For instance, in case your video is about baking a cake, your video would possibly embrace sections on baking tools or cake tendencies like geode truffles. In the event you add timestamps to mark these sections, a consumer may not discover your video when looking for “find out how to make a cake” due to competitors for this key phrase, however they might discover it looking for “find out how to make a geode cake.”

You possibly can manually add a timestamp or add and edit computerized video chapters with YouTube Studio.

14. Add a call-to-action (CTA) in your video and video description.

Calls-to-action are a robust solution to foster engagement. A CTA that gives worth not solely encourages likes, subscribes, and shares, it might probably additionally enhance viewer engagement metrics. This could increase your video’s visibility in search outcomes and prompt video options.

For max effectiveness, differ your CTAs. On one video you would possibly do a verbal CTA asking viewers to love, subscribe, or share. For an additional video, ask your viewers to bookmark your video or click on shared hyperlinks in your description.

You will additionally wish to ask your viewers to share feedback and suggestions. These actions aren’t simply worthwhile for consumer expertise. In addition they give indicators to YouTube that your video is participating and providing worth to your viewers. Take a look at these call-to-action examples for inspiration.

15. Overview YouTube search analytics.

Whereas analytics are helpful for monitoring progress towards your targets, you may as well actively use this knowledge to enhance your YouTube search engine marketing.

Say you are making an attempt to determine why site visitors instantly jumped up for certainly one of your movies. It is likely to be that your video is rating for a well-liked key phrase. Or a well-liked web site not too long ago added your video.

You possibly can dig into the video-specific knowledge and see why that bounce occurred. Then you possibly can work out find out how to optimize different movies with the identical ways.

YouTube analytics may also enable you to anticipate key phrases which might be growing in recognition. Optimizing your movies for these key phrases early on provides you a greater likelihood of rating increased in these search outcomes.

Lastly, your analytics might help you higher perceive your viewers. It is common to start out a YouTube channel with an supposed viewers after which see these demographics shift over time. Analyzing the age, location, and pursuits of your real-time viewers might help you make good modifications.

16. Non-compulsory: Depart a pinned remark by yourself video.

Leaving a remark in your video may appear excessive, but it surely’s a sensible technique. Not solely do extra feedback enhance your video’s rankability, however they’ll generate excessive ranges of viewers engagement. A pinned remark might end in a whole bunch of replies, prefer it did for Matt D’Avelia under:

Remember to go away an interesting remark that furthers the dialog or affords extra worth for readers. Right here at HubSpot, for instance, we go away a useful resource pinned in order that viewers can additional their information on the subject. Take a look at this submit for extra on YouTube remark administration.

1. Select a goal key phrase on your video. This is usually a subject, a query, or a extremely particular question. In the event you’re undecided of the correct goal key phrase, use a key phrase analysis software, or just discover YouTube’s current content material library for inspiration.

2. Embrace the goal key phrase within the file title. Don’t use areas between every phrase, however quite dashes (-) or underscores (_).

3. Embrace the goal key phrase within the title. Subsequent up, work the goal key phrase into the title of your video, however be artistic, and make sure you do it naturally. You don’t need the title to easily be “.” The title is the very first thing customers will see, so attempt to create intrigue and curiosity whereas promising to assist the viewer indirectly.

4. Embrace the key phrase, in addition to key phrase variations, within the video description. The video description is the lifeblood of your YouTube search engine marketing technique. Write a pure description with 1-2 mentions of your goal key phrase, in addition to variations of this key phrase.

5. Add associated tags to your video. Whereas most customers don’t use tags to search out movies, they might help the YouTube algorithm categorize your video and serve it to the suitable viewers. Add round 5-8 trade tags, being positive to not overdo it so that you just’re not flagged as spam.

6. Add your video class. Whereas not as particular as tags, classes assist customers discover your video and assist the YouTube algorithm perceive what your video is about. Classes come into play on the house web page, the discover web page, and the sidebar menu.

7. Add a customized video thumbnail. Create a thumbnail that features both a variation of your key phrase or a brief phrase that would generate clicks (like “1,000 natural followers, quick!”). As talked about, you’ll have to confirm your YouTube channel to get entry to customized thumbnail uploads.

8. Add subtitles and closed captions. Subtitles and closed captions are a much-needed accessibility element of your movies. In addition they not directly enable you to optimize for YouTube search by giving YouTube a textual content model of your video content material.

9. Add playing cards and finish screens that tie into the subject of your video. Playing cards are equal to inside and exterior linking, and finish screens permit you to interact viewers throughout these vital previous few seconds when a viewer is likely to be tempted to click on to a different piece of content material.

10. Add hashtags to your video. Hashtags are totally different from tags. They present up above your video title and enable you to enhance attain and authority by additional signaling what your video is about.

11. Create a playlist about your overarching subject. Among the finest methods to optimize YouTube movies is to create playlists. Discovering just a few associated movies and placing them in a playlist is not going to solely entice extra viewers, however it’s going to additionally assist the YouTube algorithm perceive how your video pertains to others in your add library.

12. Non-compulsory: Depart a pinned remark to generate engagement or present extra worth. As a model, you possibly can and will remark by yourself movies — not just for replies to your commenters, however to supply extra worth to readers.

Now, a lot of the search engine marketing suggestions above depend on you discovering a key phrase and selling your video accurately. And never all of these suggestions may be carried out by means of YouTube alone. To get probably the most bang on your videography buck, contemplate a number of the instruments under to optimize your video for search.

1. HubSpot search engine marketing Advertising Software program

Our search engine marketing advertising software program, developed right here at HubSpot, lets you discover fashionable key phrases for creating content material and organizing key phrases into groupings — what we name “subject clusters.” By sorting your content material into subject clusters, you possibly can oversee which items of content material are associated to 1 one other, which kinds of content material you might have deliberate, and what you have already created.

Whereas the key phrases you uncover in HubSpot mirror their recognition in a normal Google search, many of those subjects may even produce movies on Google’s search engine outcomes pages. In these circumstances, you possibly can create subject clusters which have each weblog and YouTube content material belonging to them.

Clustering your content material — and linking from movies to weblog posts, and vice-versa — may give you extra authority within the eyes of Google and YouTube, whereas supplying you with extra methods to seize site visitors from the individuals looking out your subject.

Professional tip: HubSpot integrates with YouTube for helpful dashboards and efficiency monitoring.

2. Ahrefs Key phrases Explorer

Ahrefs is a complete search engine marketing platform that lets you monitor a web site’s rating, estimate the natural site visitors you’d get from every key phrase, and analysis key phrases for which you would possibly wish to create new content material.

One fashionable function of Ahrefs is Key phrases Explorer, which lets you search for particulars associated to a key phrase you are interested by. And as you possibly can see within the screenshot above, you possibly can filter your key phrase outcomes by search engine — together with YouTube.

Ahrefs Key phrases Explorer provides you a key phrase’s month-to-month search quantity, what number of clicks for movies rating for that key phrase, associated key phrases, and extra.

3. Canva

You would possibly know Canva as a design template for creating every kind of playing cards, images, logos, and extra. It simply so occurs this fashionable product has a Thumbnail Creator only for YouTube movies.

As said within the suggestions above, thumbnail photos are vital to selling your content material in YouTube search outcomes and attractive customers to click on in your video. Utilizing Canva’s Thumbnail Creator, you possibly can create the right preview picture on your video in 1280 x 720 pixels — the thumbnail dimensions YouTube requires.

4. vidIQ Imaginative and prescient

It is a Chrome extension, obtainable by means of Chrome’s internet retailer within the hyperlink above, that helps you analyze how and why sure YouTube movies carry out so effectively. This consists of the tags a video has been optimized for, its common watch time, and even how rapidly that video is likely to be gaining site visitors.

The vidIQ software then provides an search engine marketing “rating” you need to use to create content material that performs (or outperforms) the outcomes you already see on YouTube.

5. TubeBuddy

TubeBuddy is an all-in-one video platform that helps you handle the manufacturing, optimization, and promotion of your YouTube content material. Its options embrace an computerized language translator (which helps you rank for non-English key phrases), a key phrase explorer, tag recommendations, a rank tracker on your printed movies, and extra.

6. Cyfe

Cyfe is a big software program suite that gives, amongst different issues, a YouTube analytics platform. On this platform, you possibly can observe efficiency on YouTube and in your web site.

Along with site visitors analytics, Cyfe can present you which of them key phrases you are rating for and which of them are hottest throughout numerous serps. Sounds so much like Google Analytics or Moz, proper? That is as a result of Cyfe has knowledge from each of these instruments, and extra, constructed into it.

Begin Optimizing YouTube Movies

Video advertising is essential for companies and creators. It doesn’t matter what search engine marketing tip or software you begin with, a profitable YouTube channel begins with good content material. Be certain that your viewers have one thing high-quality and related to observe once they discover you.

Optimizing your YouTube movies might help entice extra views and construct group — and result in extra conversions and gross sales. So, begin right this moment and watch your YouTube channel develop.

Editor’s notice: This submit was initially printed in March 2013 and has been up to date for comprehensiveness.