What is the RCA/detail for 5G registration failure cause “ILLEGAL ME”?

5G NR
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1

Hi, what is the RCA/detail for 5G registration failure cause “ILLEGAL ME”? Is it due to blacklisting? Or anything else can also be the reason? As per 3GPP TS 129.524; one reason can be blacklist. Can their be other reasons? Any doc. reference on this?

2
  1. Illegal UE
  2. 5G Service not Allowed
  3. PLMN not Allowed
  4. Tracking Area not Allowed
  5. Roaming not allowed
  6. No suitable cell in Tracking Area
  7. Congestion
  8. N1 mode not allowed
  9. Non 3GPP Access to 5G core network not allowed
  10. Serving Network not Authorised

Source: Techplayon

3

OK. 3GPP ref. for these causes? I mean which is the 3GPP release doc. for this?