In the Aleph environment, when a cataloger presses F3 in the MARC tag of call number (050), they can see "all" similar call numbers. This helps them to decide the call number for the record they are working on. The system does not differentiate whether these are physical or electronic resources, or whether they have holdings. However, in the Alma environment, when in the same call number (050) MARC tag, it is not possible to see "all" call numbers of records in the system, especially not for electronic resources. This significantly increases the difficulty for catalogers in deciding the call number. Even for electronic resources, we hope that each call number is unique. Can we see "all" call numbers, regardless of whether they are physical or electronic, at once?