RFC1345, in turn, references the Unicode 1.0 standard. I wasn't
able to find a copy of the 1.0 standard, or find an appropriate
reference within the later standards.
Regardless, you should be able to use the table from RFC1345 to
confirm that this is MacRoman (once you figure out how to read the
table which, I must admit, I found to be challenging :-).
Another good source of info is unicode.org. For example, here's the
MacRoman table listed out with Unicode entity names:
If that table matches RFC1345, then that means these encodings are
equivalent. Hmm, the RFC1345 doc includes '??' for a few entries in
its table. The unicode.org document contains character info for all
256 values. You'll be able to thus compare the vast majority of
characters, but not all.
It lists all the various "legacy" macintosh encodings. I don't see
the mention of an encoding of "macintosh" anywhere; it only refers to
"roman" (which is also the default encoding of those legacy systems).
Having said all of this, I'm almost 100% sure that "macintosh" and
"macroman" are identical.