There was an email thread around the first week of January on the subject of declaring "enum" types, meaning types that should have one of a fixed set of values. There were two ways noted to declare such a type:

1) In the field's "attribute" page, have a tag reading:

[[possible values:=value1,value2,value3]]

2) In the field's "type" page, have tags reading:

[[Enum mapping:=value1=1]]
[[Enum mapping:=value1=2]]
[[Enum mapping:=value1=3]]

Which of these is recommended/supported? Or is it both? (In theory, there's no conflict between the two.)

Tied in to this is the more general question of whether descriptive information like this should be stored in "attribute" or "type" pages. I suspect this question will get more important as SMW gains more structured features, like, say, OWL exporting, and forms for editing data (I'm working on something involving the second one).

I can think of good arguments either way:
- if you put the data in "attribute" pages, you don't have to create a custom type for each field that you want special handling for.
- if you put the data in "type" pages, you can have special handling for relations, not just attributes (if you ever needed such a thing). Also, you could have different attributes for the same type, with all the same properties (if don't know if you'd ever need that either).

Does anyone have any thoughts on this?