Re: How to write Build-Depends
> This explanation is based on Section 7.4 of Debian Policy.
> However, Section 2.3.5 says:
> All packages should use virtual package names where appropriate, and
> arrange to create new ones if necessary. They should not use virtual
> package names (except privately, amongst a cooperating group of
> packages) unless they have been agreed upon and appear in the list of
> virtual package names.
(except privately) applies here.
But I agree it might be better to define what is "privately".