MP.L2-3.8.8 Shared media
What the standard requires
Prohibit the use of portable storage devices when such devices have no identifiable owner.
Quoted verbatim from NIST SP 800-171 Rev 2 (NIST CPRT), which is in the public domain.
Cross-framework mappings
No cross-framework mapping is seeded for this control. That is stated rather than filled in: a mapping nobody authored is worse than a gap you can see.
Track MP.L2-3.8.8 with evidence behind it
In CMDash this control is a row with an owner, a status, uploaded evidence kept with its full history, and an export an assessor can read.