Multiple Settings in a Cue

Hello. I'm part of the Seneca College student who are implementing the
WebVTT spec for Mozilla.

The syntax rules state, "Each component must not be included more than once
per WebVTT cue settings string." The parsing rules allow for duplicate
settings implicitly because it makes no such check. The splitting on a
space creates a list, not an ordered list. That means a cue with duplicate
settings will parse but with unpredictable results.

Question. Should this simply be left as unpredictable behaviour? Or should
the parser make the behaviour predictable? If the settings could be
tokenized in to an ordered list then either it could use the first or last
duplicate setting (last should be easier).

My feeling is that it should remain unpredictable because the syntax states
only one is allowed and therefore duplicate settings should not be
supported. If this is the case, it might be useful to have a note in the
setting paring section stating that while duplicate settings will be
parsed, the behaviour will be unpredictable.

http://dev.w3.org/html5/webvtt/#parse-the-webvtt-settings
http://dev.w3.org/html5/spec//common-microsyntaxes.html#split-a-string-on-spaces

Thank you,
Kyle Barnhart