🚀 go-pugleaf

The following appeared in a posting to the net:

  >[lots of stuff deleted]
  >..........................That is, if I include
  >the line:
  > \font\opt12=optima at 12pt
         ^^^^^^
  >
  >[lots more deleted]

It is not important (to me) why this was posted, but isn't this incorrect
syntax? (According to the poster, no syntax error was reported.) The TeXbook
defines font assignment as

     \font<control sequence><equals><font identifier>

but \opt12 is a control sequence followed by two digits (category code
`other')! Neither the poster, nor followup mentioned this. My question:
Does \font behave like \def in this context? (I could test this but my TeX
is (sadly) not easily available for some time.) That is, would the following

\font\opt12=optima at 12 pt
\font\opt10=optima at 10 pt
\opt12

produce the error message ``Use of \opt does not match its definition''?
I find no documentation in the TeXbook on this. (Or is this one of those
verdammte cases where it is ``documented'' in one of the exercises?)

Thanks in advance,

Dan Luecking.