add 505$t should be included in title search
The 505$t subfield should be included in the title search.
Here is an example of a situation where that is valuable. If a library user is searching for Kurt Vonnegut's "Cat's Cradle" and uses the Title search, they will only find the actual work "Cat's Cradle". However, this book is also contained in short story compilations. They will miss this short story compilation which may better suit their reading needs.

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Kristin Suda commented
Many of our libraries own pre-loaded devices like Kindle's etc. the 505 field contains the titles on the devices. Having the 505 field available as a title search is extremely important for both patrons and staff.