Tag ID, unique and automatically created
Used internally for comparing typed-in tags to existing tags. Tags should be all lowercase, but otherwise as would be displayed on the page.
Because most tagspace URL implementations are lowercase, or at least do not penalize users for entering tags in lowercase (even if the tag should be capitalized, e.g. “Intel”, “XML”), this field should be in lowercase (except, ideally, for percent-encoded octects).
This does make the assumption that “apple” and “Apple” are the same tag. This is somewhat limiting but is the de facto standard on the Web and is less confusing for users.
In PHP-like pseudocode, this field can be generated from tags as such:
$link_as = percent_encode_special_chars(lowercase($tag_as_displayed));
Simply how the tag should be displayed. Unicode, no special encodings… if the tag is “<abbr>” than this field should say “<abbr>”. HS-CMS or rendering engines need to convert the special characters properly (in this case, to “&<abbr&>” for HTML/XHTML pages).