Individuals with no surname vs. an unknown surname

[Norwegian-Sardines]

In v5.5.1 of the GEDCOM specification on page 55 the following example was indicated for NAME_PERSONAL:

Examples:
William Lee (given name only or surname not known)

This is contrary to what my software does for persons with an unknown name.

GEDCOM v7+ needs to make it obvious that there is a difference between these two conditions (no surname vs unknown surname).

For example:
1 NAME Olaf Torsson {no surname}
vs.
1 NAME Olaf // {unknown surname}