Under this answer here on Academia StackExchange, Xander Henderson and I observed that there seems to be a large difference between the United States and, for instance, Germany regarding how specific some universities and colleges tend to be with style guidelines for PhD theses (and also other theses):
When I did my PhD in Germany (at Ulm University) there was not style or formatting guide at all. There were merely two general regulations about the processes of awarding PhDs (in German: "Promotionsordnungen") - one for the entire university and one for the department. They said that a PhD thesis must contain a title page, a table of contents, a summary, a complete bibliography, a CV, and a certain declaration, but aside from the contents of this declaration no details whatsoever were given (it was not even specified what has to be on the title page).
From experience, things seem to be similar at other German universities.
On the other hand, it seems to be rather common that many US institutions have quite detailed style guides for PhD theses.
Examples: The format guide of UC Riverside specifies the page margins and says that the text has to be double-spaced. The University of Chicago has similar requirements in this document. The MIT gives their students a bit more choice, but still specifies that "[t]he text of the thesis may be single-, double-, or one-and-a-half-spaced", see here. (Thanks to Xander Henderson for providing those links under the answer linked above.)
I understand why it can, for instance, make sense to specify that certain things have to be on the title pages. But I'm wondering why one would regulate, for instance, the page margins or the spacing between the lines.
Question: I'm interested to understand the rationale - and the cultural or institutional context of this rationale - for having such detailed formatting requirement for a thesis at all and, if one decides to have them, for having them at an institutional rather than at a departmental level.
The "cultural or institutional context" part is important: I'm not looking for a mere list of features or consequences of having such a guide (e.g. "specifying the page margins and the spacing makes it easy to compare the length of different theses"), because this alone is likely to provide little insight. Rather, I would like to understand the context: why do some US institutions find those features and consequences of having a detailed style guide sufficiently important that they choose to impose those restrictions?
Note: I explicitly took the United States and Germany as examples since the question popped up in a dicussion of US vs. German universities (and because I know the German system much better than other countries). If you know the situation in a different country where such detailed style guides are common, I'm of course also very interested to learn the reasons for doing this there.
