Prov-WD: Usage/GenerationDescription -> EntityDescription relation

[Ole Streicher]

Hi all,

the strictness of the Usage/GenerationDescription -> EntityDescription
relations is not properly given. The text says (pg.24+)

"When related to the UsageDescription or GenerationDescription, the
attributes of EntityDescription (see Section 2.5.2) help to describe the
category of entities expected as an input or an output in an activity.
For example: the input bias files must be in FITS format (relation to a
DatasetDescription with contentType}=application/fits, or the red, green
and blue channel images must be in PNG or JPEG format."

Specifically, it is unclear how the EntityDescription of an actually
used Entity is related to the EntityDescription of the UsageDescription
(or GenerationDescription):

* MUST the EntityDescription of an Entity that is linked to Used be one
of the EntityDescriptions listed in the UsageDescription? (i.e. is this
strictly?)

* SHOULD the EntityDescription of an Entity that is linked to Used be
one of the EntityDescriptions listed in the UsageDescription? (i.e. may
there be exceptions?)

* MAY  the EntityDescription of an Entity that is linked to Used be one
of the EntityDescriptions listed in the UsageDescription? (is this just
best practice?)

(MUST/SHOULD/MAY as defined in RFC2119; same for GenerationDescription)

Also, the links between ActivityDescription and UsageDescription resp.
GenerationDescription are not explained at all. And although one could
assume that the the UsageDescription MUST (RFC2119) be linked to the
ActivityDescription of the Activity that is referred to in the
Used/WasGeneratedBy relation, this restriction is not mentioned.

The same is true for the relation between ActivityDescription and
ParameterDescription resp. ConfigFileDescription in the
ActivityConfiguration package.

Best regards

Ole