Subtags for subextensions

[CSymes]

Is there a way to classify subextensions to use additional tags to the actual extension?
Say you have file example.x.y, and while identify recognises extension .y, the .x.y denotes additional information that would be beneficial to have access to.
For instance, in the C# domain, several IDE tools generate .designer.cs files and it would be useful to tag these as (e.g.) autogenerated in addition to the standard C# tags.

Is this level of tagging too granular for this tool?
Is this level of pattern matching currently supported?

[asottile]

there isn't -- more information in #125 / #119