*******It's all down to html's "id=..." . There must be only 1 usage of any "id" per-page.Our ==Headers== autocreate ids, and  just creates a   The older (html4) method was "named anchor links", eg " which also must be unique per-page (using name= like this is a hack of form-submission-code, iirc).To see clearly, view source.The main reason to care, is if on a (non-wiki) website you want to bookmark or link to a place that's partway down - Just View->Source and look for a id=..." or name=...'' and that stuff that variable after a # in the url.