I don’t know if ‘(import ...)’ is standard either (sure it is as part of
‘define-library’, but I didn’t find it on its own in r7rs.pdf),
(import ...) is standard in both R6RS and R7RS, and supported by every
serious implementation of those standards. Please spread it.
R7RS talks about "programs" and "libraries". These are technical terms
with precise meanings.
A "program" corresponds to your typical Scheme script. IIRC it _has_ to
start with (import ...).
A "library" is a (library ...) [in R6RS] or a (define-library ...) [in
R7RS]. You can type (import ...) inside either.
> https://srfi.schemers.org/srfi-97/srfi-97.html:
>A SRFI Library can be referenced by number, as in
>(srfi :1),
(srfi 1) is problematic, since ‘1’ is not an symbol (#{1}# is, but
that’s not what has been choosen in SRFI 97).
In R7RS non-negative integers can be library name parts. Since these
library names look natural, it would be good to backport this to R6RS
implementations.
The colon causes endless grief when mapping library names to file names.
For example, look at all the %3a in
https://github.com/arcfide/chez-srfi. That's not even the worst of it.