Capitalisation of "MacKay" etc when on-screen credits are all in upper-case

What is the house style where credits are displayed on-screen in all upper-case (or occasionally all lower-case) and the surname is conventionally written in CamelCase?

I presume that all lower-case is treated as an affectation and that a character "john smith" (on-screen) should always be converted to "John Smith". I realise that the capitalisation of titles is different, hence the correct entry for tt0161140 is "dinnerladies" (as written on-screen) and not "Dinnerladies, " DinnerLadies" or "Dinner Ladies".

For example, someone who is listed as MACKAY or MCKAY in the on-screen credits. Should that be transcribed as Mackay or Mckay, or as MacKay or McKay, with the latter camel-case being conventional way that a Scottish/Irish surnames are written because the Mac is a son-of prefix.

I can't see any mention of this on the character/cast help page.



Also, am I right to correct IMDB credits of the form "Head teacher" or "Security guard" where the second word has not been capitalised in IMDB although it *is* shown as "Head Teacher" (or "HEAD TEACHER") in the on-screen credits. There seems to have been a submitter or group of submitters who have submitted a lot of credits where all words apart from the first are not capitalised - and often I find that the on-screen credits do have every word capitalised apart from prepositions and articles, so it's not a transcibe-as-seen problem. Was IMDB's house style ever for "Head teacher" etc, at some time in the past?