With the file percent.1 below and an 80-column screen the file percent.1
below processed with

    M-x woman-find-file percent.1

gives

    %%%%Some percents  one two three  four five six  seven eight
        nine ten eleven twelve thirteen fourteen fifteen.

Where I expected

    %%%%Some percents  one two three  four five six  seven eight
    nine ten eleven twelve thirteen fourteen fifteen.

It seems woman.el uses fill-region-as-paragraph and that
adaptive-fill-mode, which is t by default, causes the "%"s in the input
to become a fill prefix.  I think that shouldn't be done, that instead
woman.el should control all indentation.

It seems this only affects roff source where the paragraph flowed is a
single line of the input.  You can make a very long input line to see
multiple hanging lines in the output.  Various other prefix characters
in adaptive-fill-regexp are affected similarly, eg "#" instead of "%".

I get some joy from forcing adaptive-fill-mode off in
woman-decode-region.

2012-10-27  Kevin Ryde	<user42@zip.com.au>

	* woman.el (woman-decode-region): Let-bind adaptive-fill-mode nil so a
	paragraph consisting of a single long input line "%%Foo ..." doesn't
	have "%" treated as a hanging indent.