From W3C Wiki
When you are writing a specification, it might happen that you are not sure about Extensibility of your specifications. Extensibility can cover many meanings at the same time.
wiki topics work better when they answer questions rather than ask them. a PPR:Pattern is a solutions to a frequently-seen problem. Not quite the same issue, but related, see PPR:DontNamePagesThoughtsIssuesIdeasOrOpinions
Does that mean you create a specification which can accept new features, extensions. This can be done
- with a precise defined mechanisms.
- or without mechanisms.
How extensibility appears in specifications?
It can be because of the definitions of features because of the
- behaviour of implementations (you don't have a specific answer)
- specific implementations (for example, black and white screen versus color)
- uncertainty on the features advantage
- future needs.
So If you want to create extensibility you might need to define a precise mechanism to do that
- Examples in the W3C Specs? Pbs and Advantages.
- Examples outside W3C Specs?
- Benefits and Risks for Developpers?