empty param values in votable

[Carlos Rodrigo]

Thanks a lot for your answer.

I will have to add value="" to FORMAT=METADATA responses.

Just a comment:

> Historically, PARAM was intended to represent a table parameter,
> in the sense of an item of per-table (rather than per-column) metadata.
> Given that, the requirement to have a value makes sense.
> 
> In some recent usage, the PARAM element has been co-opted (or abused
> due to linguisitic confusion?) to specify a parameter in the sense
> of a variable for which the user can supply a value, and in that
> context giving a value attribute on the PARAM element doesn't
> make much sense.

I would say that the use of a PARAM to specify a parameter in the sense of a variable for which the
user can supply a value is not so recent. It is in SSAP (FORMAT=METADATA queries) since many years
ago. That's why we use it in our filter service, copying the SSA idea.

Thanks again

Carlos