IEC 61850-1 and IEC 61850-6 mentions the functional structure and designation coding of IEC 81346 to be used for the object hierarchy. However the MMS Identifier does not support the mandatory special characters according to IEC 81346-1 Rule 7 and Rule 35. The result is a naming that will not always be able to comply with IEC 81346-1.
Please change the character set so that all characters used in the designation coding of IEC 81346-1 are supported for the MMS identifier.
Allow the characters ‘=’ (equal) , ‘-‘ (minus), ‘+’ (plus), ‘#’ (hash), ‘<’ and ‘>’ (angle-brackets) in the MMS Identifier.
NOTE/FYI: The '.' (dot) and '/' (slash) are also defined in 81346, but since they are already used in the MMS and/or ACSI object reference, they cannot be part of the MMS identifier. Fortunately, these two chars are optional and their meaning can be reflected using the six chars above.
This issue was also raised as DK2 in the comments for the IEC 61850-8-1-AMD1-ED2_57-1823e-CDV document.
The names used on an IED and thus appearing in MMS as names / identifiers are all product related (-), and therefore a leading '-' can be assumed, if needed, but nothing inside the names is needed. The recommended functional structure and designation of IEC81346 ('='), and may be in future also the location related ('+') designations are recommended for functional names based on the part 6 process / substation / Line structures. Here exist no character set restrictions. Further, inside descriptive texts on the IED (d, dU attributes) also all mentioned characters can be used. Therefore no extended character set for MMS level naming is needed.