Regarding categories, I must be missing something. Found no reference to a field called
category_nickname in 1.5.2 or 2.0 either in the database or in the code.
As for the user_nicename vs. user_nickname:
In 1.5.2 both
user_nickname were in the
user_nicename was the sanitized (I think that's the right word) version of
user_nickname meaning "My Nickname" is made into the nicename of "my-nickname".
user_nicename is still in the
wp_user table but it is the sanitized version of
user_login field. The nickname field was moved into the
wp_usermeta table with a 'meta_key' of 'nickname'. One interesting point is that when a new user is added (or registers) the
nickname fields are pretty much the same value (except
user_nicename is sanitized). Subsequently, the
nickname can be changed by the user or the administrator.
In 1.5.2 the 'nicename' was tied to the 'nickname' so that meant that the 'nicename' changed if the 'nickname' changed. But, in 2.0 the 'nicename' is tied to the
user_login field so the 'nicename' nevers changes because the
user_login can never change. Don't know if that was intentionally done by the developers...
One other note--if your plugin is using something like the
get_userbylogin function, the 'nickname' is NO LONGER accessed with the variable
nickname instead. But,
user_nicename is still valid. See Author Templates for more info on this.
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