Make 3.6.2 (Preserve Distinctions) a user option

I propose revising 3.6.2 to be a user option rather than requiring it to 
be always on. I include two possible rewrites below.

UAAG20 3.6.2 currently reads:"3.6.2 Preserve Distinctions: When rendered 
text is rescaled, distinctions in the size of rendered text are 
preserved (e.g., headers continue to be larger than body text). (Level A)"

This actually conflicts with other guideline documents that actually 
recommend that the user have the option to display all text in the same 
font, including uniform size. Here are two examples from ISO 9241-171 
item 10.3.2:

    EXAMPLE 1    A word processor contains a "draft mode" which shows
    all document text in a single, user-selectable font, colour and
    font-size, overriding any formatting information specified in the
    document itself. When the user encounters small text that they have
    difficulty reading, they can switch into this mode and will still be
    viewing the same section of the document, but at a size they have
    already selected as meeting their needs.

    EXAMPLE 2       A user has difficulty reading small text on the
    screen, so they set a "minimum font size" preference valuein the
    operating system's control panel. The Web browser respects this
    setting and automatically enlarges any text that would otherwise be
    smaller than this size.


Here are two possible rewrites:

    "3.6.2 Preserve Distinctions: /The user has the option that /when
    rendered text is rescaled, distinctions in the size of rendered text
    are preserved (e.g., headers continue to be larger than body text).
    (Level A)"

    "3.6.2 Preserve Distinctions: /The user has the option to preserve
    distinctions in the size of rendered text when that text is rescaled
    /(e.g., headers continue to be larger than body text). (Level A)"

The first merely prepends the stock phrase "The user has the option". 
Unfortunately the document only use the variations "The user has the 
option TO" and "The user has to option OF", neither of which would fit 
the rest of the sentence, so I had to introduce "The user has the option 
THAT". The second is revises the wording more thoroughly in order to use 
the already-used variant "The user has the option TO". I actually prefer 
the second, but either would be acceptable.


    Thanks,
    Greg