Hi @television
Based on your description, I tested a similar scenario in my environment by setting up multiple worksheets. I used S1 as the main sheet containing the list of names, while S2, S3, S4, and S5 contain the signup lists.
For example, if "Word" appears in S3, S4, and S5, I used the following formula in S1 to return the names of the sheets where the name was found:
=TEXTJOIN(", ",TRUE,IF(COUNTIF(INDIRECT("'"&{"S2","S3","S4","S5"}&"'!A:A"),A2)>0,{"S2","S3","S4","S5"},""))
The formula returns the matching sheet names in the cell, for example: S3, S4, S5

Additionally, you can refer to the following AI-generated answer for another approach to your scenario.
I hope this helps. If I have misunderstood your scenario or the way your worksheets are structured, please feel free to correct me and provide more details about your setup.
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