: In the legal system (specifically California), the SER-001 form is a Request for Sheriff to Serve Court Papers . It is used when a party needs a sheriff or marshal to serve documents like a summons or subpoena .

: In neuroimaging and EEG analysis, .set is a common file format (EEGLAB). Users often work with files like sub-001.set to store raw or processed brain activity data . 3. Trading Card Games (TCG)

: Players often refer to the "First Chapter" release as Set 1 or Set 001 , which often holds higher value due to limited early print runs