[Python-Dev] Edits to Metadata 1.2 to add extras (optional dependencies)

["Martin v. Löwis"]

> But note that the RFC also says that the preferred solution to the
> problem that X-fields are intended to solve is an easily accessible
> name registry and a simple registration procedure.  If Martin's "be
> prepared for a ten-year period to acceptance" is serious, what should
> be done about such a registry?

I'm happy for PyPI to host such a registry. A specificaion for the 
registry should be part of the PEP for the 1.3 format, but I would 
propose this structure (without having researched in detail what
other registries feature, but with a rough idea what IANA registries
typically include):

- name of metadata field
- name of registrant (individual or PyPI package)
- contact email address (published)
- expiration date; by default, extensions expire 1 month after
   their registration, unless renewed; maximum expiration time is
   5 years
- English description of the field
- regular expression to validate the field

Deleting undesired extensions would not be possible, instead, one
would have to create another extension if the syntax or semantics
changes

Regards,
Martin