UCD elements

[Martin Hill]

This means then that new services that support, say UCD2s, cannot be used by 
older services or clients that have no knowledge of UCD2s...

Marco C. Leoni wrote:

> Hi Tony,
>    I think the services should say the UCDs version they are using or 
> can understand/support: the registry - as a service itself - will 
> specify the UCD version used to create the metadata describing itself.
> 
> 
> Cheers,
>    Marco
> 
> 
> 
> Tony Linde wrote:
> 
>> I agree with Clive. We need some way of saying that version X of registry
>> uses UCD1 and version X+1 will use UCD2 or whatever. Or each registry 
>> says
>> which versions of individual standards it supports (UCDs, Identifiers, 
>> etc).
>> We certainly shouldn't stuff every variant of every standard into the
>> metadata.
>>
>> Tony.
>>
>>  
>>
>>> -----Original Message-----
>>> From: Clive Page
>>> Sent: 02 July 2004 09:11
>>> To: registry at ivoa.net
>>> Cc: VOTable mailing list
>>> Subject: Re: UCD elements
>>>
>>> On Thu, 1 Jul 2004, Martin Hill wrote:
>>>
>>>   
>>>
>>>> We will need (at latest when we introduce UCD2 over UCD1+) 
>>>> simultaneous UCDs of different versions in single metadata     
>>>
>>> documents   
>>>
>>>> (so both older and newer tools can use them).
>>>>     
>>>
>>> Is that really necessary?  As I understand it there is a unique 
>>> one-to-one mapping from UCD1 to UCD1+, which should be easily 
>>> encapsulatable in software, or even a Web Service.  I'm not sure if 
>>> that's true too of UCD2, but if it isn't doing conversions is going 
>>> to be labour-intensive.
>>> Putting duplicated UCDs of different versions in each data file seems 
>>> a bit of overkill if that's true.
>>>
>>>
>>> -- 
>>> Clive Page
>>> Dept of Physics & Astronomy,
>>> University of Leicester,
>>> Leicester, LE1 7RH,  U.K.
>>>
> 
> 

-- 
Martin Hill
www.mchill.net
+44 7901 55 24 66