This isn’t restricted to ‘page’: there’s a whole set of PDF fragment identifiers [0,1]. Most notably ‘zoom’, ‘view’ and named destinations, but there are others.
Interesting! And it seems like they are fairly well-supported among major browsers, with the exception of Safari [0].
Writing links by hand is rather cumbersome, though, they ought to be better exposed in PDF viewers. It certainly doesn't help adoption when the list of allowed parameter values is locked in a proprietary spec!
view=<keyword>,<position>
The arguments correspond to those found in [ISOPDF2] 12.3.2.2
"Explicit destinations". <keyword> is one of the keywords defined
in [ISOPDF2] "Table 149: Destination syntax" with appropriate
position values.
[ISOPDF2] ISO, "Document management -- Portable document format --
Part 2: PDF 2.0", ISO 32000-2:2017, 2017.
(Strictly speaking it's the 2020 revision which incorporates some errata. I don't know if the final standardized 2017 version was made freely available)
[0] https://www.rfc-editor.org/rfc/rfc8118.html#section-3
[1] https://pdfa.org/pdf-fragment-identifiers/