[NNTP] Clarification of intra-document references in RFC 3977

Following a discussion with Alfred Hönes, who reported:

 > clarification of intra-document ref.
 >
 > Within Section 2 of RFC 3977, the first paragraph on page 6 says:
 >
 >                       [...].  In some cases, however, they do assume that
 >     the currently selected newsgroup (see the GROUP command,
 >     Section 6.1.1) is invalid; when so, this is indicated at the start of
 >     the example.  [...]
 >
 > The "currently selected newsgroup" is introduced in Section 6.1 (see
 > next quotation below); as such, the clause therein,
 >
 >        (see the GROUP command, Section 6.1.1)
 >
 > should more appropriately have been replaced by:
 >
 >        (see Section 6.1)
 > or:
 >        (see Section 6.1 ff.)

I do not know well what to do with that.
Here is my answer to Alfred:

I do not think the text should be changed this way.
In Section 6.1.1, we have:

    The GROUP command selects a newsgroup as the currently selected
    newsgroup and returns summary information about it.