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If you mean Catalog back-ups, you can safely delete any but most current ones if you wish. Only reason to keep earlier one might be if you split a Catalog or made other radical changes you might otherwise want to go back to.
Welcome to the Dave.
Personally I backup once a week and keep two backups active, deleting older ones. My system seems pretty stable so that works for me.
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Thanks and enjoy the forum and LR!!