On Sep 23, 2009, at 9:19 AM, Jonathan Rochkind wrote:

> Thanks!  So $v, $x, $y, and $z should always get a "--" before them  
> -- that's sufficient logic to do it 'right'?  I guess an LCSH 6xx  
> always needs an $a first, so I don't need to worry about if a $v or  
> $x happens to come first, and shouldn't get a preceding "--".
>
> Should I do this only for 6xx with 2nd indicator 2 indicating LCSH,  
> or do people generally just do this for all 6xx?

Our ancient hardcopy MARC 21 manual says the dash preceding any of  
those subfields is a display constant, and there is no mention of  
indicator-based display logic.  So no need to worry about the  
indicators.

I suspect this is ISBD punctuation.  If so, it's probably the only  
ISBD punctuation that is, sensibly, not carried in the data.

On Sep 23, 2009, at 9:20 AM, Jonathan Rochkind wrote:

> Hey, and it occurs to me, in an HTML display, it might be better to  
> use an actual em-dash than the traditional two hyphens too?  Since  
> the LC documentation just talks about "dash" -- two hyphens is how  
> you approximate an em-dash in ascii of course, but we're not living  
> in ascii anymore!

In fact, the old MARC 21 Format for Bibliographic Data print manual  
uses the em-dash.  I would agree that the "--" is legacy, probably  
from the days of printing cards on impact printers with the old  
Library of Congress print train.

If you go for the em-dash, it will be interesting to see how long it  
takes for someone complain about the change from the double dashes.

-Tod


> Tod Olson wrote:
>> Only for certain subfields:
>>
>> Dash (-) that precedes a subdivision in an extended 600 subject   
>> heading is not carried in the MARC record. It may be system  
>> generated  as a display constant associated with the content of  
>> subfield $v, $x,  $y, and $z.
>>
>> From http://www.loc.gov/marc/bibliographic/bd600.html
>>
>> -Tod
>>
>> On Sep 23, 2009, at 9:09 AM, Jonathan Rochkind wrote:
>>
>>
>>> Hi all, I'm writing some marc record display code, and I have a   
>>> question about the 'right' way to display LCSH headings.
>>>
>>> LCSH headings are typically displayed with "--" between  
>>> components.  But looking at the MARC, it looks like the "--"  
>>> punctuation isn't  actually in the MARC field. (A rare instance  
>>> where display  punctuation isn't in the marc!).
>>>
>>> Is it correct for any LCSH 6xx field (which you know because the  
>>> 2nd  indicator is 0, right?), to add "--" between ALL present  
>>> subfields  on display?   Do I have the right logic there?
>>>
>>> Thanks for any advice!
>>>
>>> Jonathan
>>>
>>
>>