During the Alma Interest Group meeting at MLA, there was a discussion on how to search for information in the 300 field.  Someone reminded the group that the best way to do this was with an Indication rule. 

The questions concerned finding reel-to-reel tapes in their library.  So, I put together an indication rule to help with the filtering.

First you’ll need to make a set.  I did a physical title advanced search and limited to musical and nonmusical sound recordings.  (see attachment)

Save the set.

Then you’ll need to create an indication rule.  Try the Alma help for specific info on indication rules.  I found this page helpful.  https://knowledge.exlibrisgroup.com/Alma/Product_Documentation/010Alma_Online_Help_(English)/040Resource_Management/040Metadata_Management/020Navigating_the_MD_Editor_Page/Working_with_Indication_Rules

Note that there is word document with more examples toward the bottom of the above page.

Here is the indication rule that I put together.

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rule "Contains 300 with subfield a reel"

when

     exists "300.a.*reel*"

then

              set indication."true"

end

Feel free to contact me if this doesn't make sense.