Can someone please check if we really have this lower/uppercase variations in element names?

Gents, while boosting readability (think: tagging in word, indexing, etc) I often meet variations in lower upper camel whatever case for the same syllables / acronyms.
E.g. value (sometimes Value)

ID vs. Id XPath vs. Xpath Is this due to upstream nags, or did our schema always have this garden variety or is this a problem with our extraction chain (the latter I do not think)

It would be very helpful to receive some educated guesses from people other than the one currently digging hours over hours through the word document.
Thanks a bunch / Bunch :-) Stefan