Now whether it _means_ what you want it to mean is another question, 
yeah. As Andreas said, I don't think that particular example _ought_ to 
have two 856's.

But it ought to be perfectly parseable marc.

If your 'patch' is to make ruby-marc combine those multiple 856's into 
one -- that is not right, two seperate 856's are two seperate 856's, 
same as any other marc field. Applying that patch would mess up 
ruby-marc, not fix it.

You need to be more specific about what you're doing and what you mean 
exactly by 'causing the ruby library to ignore it'.  I wonder if you are 
just using the a method in ruby-marc which only returns the first field 
matching a given tag when there is more than one.



On 5/19/2011 12:51 PM, Andreas Orphanides wrote:
> From the MARC documentation [1]:
>
> "Field 856 is repeated when the location data elements vary (the URL 
> in subfield $u or subfields $a, $b, $d, when used). It is also 
> repeated when more than one access method is used, different portions 
> of the item are available electronically, mirror sites are recorded, 
> different formats/resolutions with different URLs are indicated, and 
> related items are recorded."
>
> So it looks like however the URL is handled, a single 856 field should 
> be used to indicate the location [2]. I am not familiar enough with 
> MARC to say how it "should" have been done, but it looks like $q and 
> $u would probably be sufficient (if they're in the same line).
>
> However, since the field is repeatable, the parser shouldn't be 
> choking on it, unless it's choking on it for a sophisticated reason 
> (e.g., "These aren't the subfield tags I expect to be seeing"). It 
> also looks like if $u is provided, the first subfield should indicate 
> access method (in this case "4" for HTTP). Maybe that's what's causing 
> the problem? [3]
>
> Anyway, I think having these two parts of the same URL data on 
> separate lines is definitely Not Right, but I am not sure if it adds 
> up to invalid MARC.
>
> -dre.
>
> [1] http://www.loc.gov/marc/bibliographic/bd856.html
> [2] I am not a cataloger. Don't hurt me.
> [3] I am not an expert on MARC ingest or on ruby-marc. I could be wrong.
>
> On 5/19/2011 12:37 PM, James Lecard wrote:
>> I'm using ruby-marc ruby parser (v.0.4.2) to parse some marc files I get
>> from a partner.
>>
>> The 856 field is splitted over 2 lines, causing the ruby library to 
>> ignore
>> it (I've patched it to overcome this issue) but I want to know if 
>> this kind
>> of marc is valid ?
>>
>> =LDR  00638nam  2200181uu 4500
>> =001  cla-MldNA01
>> =008  080101s2008\\\\\\\|||||||||||||||||fre||
>> =040  \\$aMy Provider
>> =041  0\$afre
>> =245  10$aThis Subject
>> =260  \\$aParis$bJ. Doe$c2008
>> =490  \\$aSome topic
>> =650  1\$aNarratif, Autre forme
>> =655  \7$abook$2lcsh
>> =752  \\$aA Place on earth
>> =776  \\$dParis: John Doe and Cie, 1973
>> =856  \2$qtext/html
>> =856  
>> \\$uhttp://www.this-link-will-not-be-retrieved-by-ruby-marc-library
>>
>> Thanks,
>>
>> James L.
>