Supported MTEXT codes

Is there a list somewhere of supported MTEXT codes?  In particular, I'd like to find out if ordinary text underlining is possible.

I see that the \S...^ code works for superscript 'stacking' - I haven't tried it out for fractions.

The \P paragraph code is inserted into saved Dxf, but it shows within the app as regular line breaks.

As mentioned, the \L...\l code doesn't seem to work, nor the \W...; width adjusting code.

If it would be a useful thing, I could spend time to test out others and report back.

I've finished looking at the underlying programming code.

The MTEXT codes that work (case sensitive) are:

\F and \f, font change.

\S, stacking; useful for super- and sub-scripting.  Only the '^' sub-code works; no actual fractions are possible without drawing in a separate line.  Examples: to produce superscript A, use \SA^;. To produce subscript B, use \S^B;.  The final semicolon ends the stacking code.

\P, paragraph.

\n, new line.  (This isn't a 'real' MTEXT code, I think, but fairly standard computer code that gets interpreted as new line.  I don't think it would be understood by AutoCAD if the drawing file was reopened there.)

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As I noted before, other text decoration like underlining is not yet supported.