Cardinality of semantic descriptors

[fosdev]

IMO, ALPS should indicate explicitly whether a semantic element is one or whether it is multiple.

C&P from Leonard r TK's on contact example (removed from spec for 00 release).

"contact" type items.

•      <!--[TK Does rt mean one or more? I thought it meant one. -LR] -->
  

The "contact"

•      ID has become the CSS class of an HTML table.
  

•      <!-- [TK again there seems to be a confusion between singular and
  

•                plural. The "contact" table contains all the contacts,
  

•                implying that this is one person with multiple names and
  

•                emails. -leonardr] -->
  

•      ID has become the CSS class of the TR elements in an HTML table.
  

[fosrias]

I can see a couple of approaches to this.

1. Use an ext to define as list.
2. Use a convention like:

 <descriptor id="item" rt="thing"/>
<descriptor id="collection" rt="[thing]"/>

3. Ignore this issue.

I think the question here is cardinality really a semantic issue. I don't think it is. I think it is a data type thing. That being said, I think using 2 to indicate this MAY be a list might be a simple and useful convention.