what to do when MASTER_SITE_SUBDIR differs?

[Mike Brown]

The primary distribution site for the source of the package I'm working 
re-porting is the developers' own site, and they (OK, we) use SourceForge
as a secondary distribution point. I'd like to list both the home site and 
SourceForge in the MASTER_SITES.

The convention seems to be that when using ${MASTER_SITE_SOURCEFORGE},
MASTER_SITE_SUBDIR is set to the SF project name.

But in this case, the subdirs don't match between the two sites, due
to SourceForge forbidding leading numbers in project names.

So I am not sure how to do this. I don't really see much precedent for 
foregoing MASTER_SITE_SUBDIR and just doing something like

MASTER_SITES=   ftp://ftp.4suite.org/pub/4Suite/ \
                ${MASTER_SITE_SOURCEFORGE}/foursuite/

...but would that be acceptable?