I expose this tissue here but it could match in part 8.1 or 6.
It refers to TISSUE 50 (IEC 61850 -7.2) = LNName starts with number?
It is said that the prefix of an Logical Node or LNName can't start with number because the MMS NamedVariable Name (MMS Identifier)doesn't allow it.
It we use an IEDNaming namestructure (Header of the SCL file), when we ask for a ACSI GetServerDirectory (Logical Devices) service (MMS GetNameList asking for the Domains of an VMD(Virtual Manufacturing Device)) the MMS Identifier returned will suffer the same problem(an MMS Identifier starting with number).
Apart from that, the restriction of MMS Identifiers to letters happened in IS0 9506(1990). Hasn't this restriction been relaxed in the IS0-9506(2003)standard? At least in the ISO-9506(FDIS)2002 it was a change mentioned:
"The restrictions on the characters that can be used as an Identifier have been relaxed to allow an Identifier to begin with a numeric character and, by extension, to consist solely of numeric characters."
Proposal
Clarify.
If numbers aren't allowed as a prefix of a Logical Node or as the first letter of an IEDName, make a restriction in the schema in part 6 of the standard and add a comment in the standard.
Discussion
Created
Status
Discussion with Herb Falk 09/02/23
New MMS release allows MMS domain to start with a number.
However, previous MMS does not allow MMS domain (i.e. in 7-2 iedName or LDName) to start with a number. CIM does not allow it neither.
Proposal: the iedName can either start with a letter (upper or lower case) or an underscore.
The underscore can be follow by an numeric character. It granted the backward compatibility AND facilitate the CIM harmonization.
25 Feb 09
Ballot Period
It is intended to keep the restriction. Need to verify in the schema.