[rfc-i] t with indent

Hi folks,

In doing Auth48 for RFC8844 I noticed that each <t> block in the final
XML seems too contain an "indent" attribute, as in:

   <t indent="0" pn="section-2-5">

While I see that the current v3 grammar seems to allow "indent" under
<t>, this doesn't seem to be in draft-iab-rfc7991bis, so it's not
quite clear what purpose it's intended for. This seems to raise two
questions:

First, do we really want this kind of layout-specific markup rather
than semantic markup? Searching for <t> with indent != 0 in the
published RFCs, I see the following cases:

- RFC 8907, S. 6.2 -- a definition list nested in another definition list

- RFC 8916, S. 5 -- a definition list indented under a hed (arguably
                    another nested definition list)

- RFC 8919 S 7.3 -- a set of Note: values introduced by a sentence
                    ending in a colon

- RFC 8934 S 4.2.2 -- an equation

- RFC 8949 S 8 -- an equation

It seems like we might be better served here by introducing some new
semantic constructs. Both nested definition lists and equations are
natural structures that would benefit from consistent layout (note:
it's possible that nested definition lists already exist; it wasn't
quite clear to me from the grammar). RFC 8919 is kind of an edge:
one could probably model it as a definition list or one could just
live with the Notes not being indented.

Second, even assuming that <t indent=...> is a good thing, it seems
suboptimal to have it attached to every paragraph in the XML. Is
there a reason why it can't simply be omitted when it is set to
the modal value of "0"?

-Ekr