Handling metadata items of the same category

What is the proper way to insert multiple metadata items of the same category, e.g., subject or title. Is it by putting every item in individual input or rather by putting them together in a single input, separating every item with comma. So, e.g., for three subject items (say white, blue, red) should I create three inputs for every item or put them in a single input?

Generally, individual inputs is the way to go. It creates more structure, and makes the data more useful down the line.

Ok, I thought so and followed this rule.
But then, the links in the Catalog Search section include only item from the first input, while all items should be there I suppose for more accurate querying the secondary services.

Could you describe more about the Catalog Search question? All the element texts should be included in the general search capabilities. If it’s a matter of display on a particular page, it might be a relatively easy matter of some theme customization.

Sticking to my foregoing example with white, blue, red keywords (= placed in a subject metadata category, each keyword in individual input), I get the following links in the Catalog Search section of the Item (I placed just a few of the links here):

http://www.jstor.org/action/doBasicSearch?Query=white
https://www.google.com/search?btnG=Search+Books&tbm=bks&tbo=1&q=white
http://catalog2.loc.gov/vwebv/search?searchArg=white&searchCode=GKEY^*&searchType=0

So in the links only the first keyword is present. I am not sure if all those catalogs allow to search by multiple keywords (I believe they do), but having all the keywords in the search criteria (here: white, blue, red) would allow to produce better results in the catalogs.

Thanks. Looks like you are working with the Catalog Search plugin, which I’m not too familiar with. You might try filing an issue there for a more knowledgeable response about how it all works.

Sure, thanks, I have just posted the issue there.