I am writing meta tags for my website. With meta, I mean SEO, like keywords and description.
I have some questions though:
Thanks
Does the DOCTYPE matter when writing meta tags?
Only in so far as it decides if you need a / at the end, and if the tag and attribute names are case sensitive.
Is meta case sensitive or not?
The tag and attribute names are in XHTML. The rest, depends on the specific meta data you are expressing.
Should I use comma between keywords or space? What if a keyword of your choice consists of two words, like "new ad"?
Meta keywords are comma separated (and all but worthless unless you run your own parser over them, search engines ignore them as they are rife with spam).
What else is important to think about in terms of SEO and meta tags?
Only description really matters, and the key is to provide useful information to display as a summary of the page (and to not use it if text extracted from the page is better for users).
Doctype sould not matter with meta tags unless you want to just be goofy and say your doctype is xml or something. Any valid doctype, or lack of doctype, is fine.
Whether tags are case sensitive depends on your doctype. XHTML wants tags to be lower case, but search engines will figure it out anyway.
Between keywords you should use a comma, if the phrase is two words the comma separates the phrases.
What else? Google has publicly stated they don't take keywords seriously anymore, but your meta description usually ends up verbatim in on the search results page. The title tag is not a meta tag, but its extremely important. SEO is a large topic, this is just very basic information.