"I Must Not Tell Lies"

[pcaehill2]

No: HPFGUIDX 109161

On another re-read of HP5, in particular the horrible Umbridge's 
horrible punishment--a thought struck me (ouch!): the scar from 
Umbridge's quill on the back of Harry's hand must stay with him, 
hmmm?  So, pondering the possibilities--

--Could "I must not tell lies" brand Harry as a notorious liar, if 
misinterpreted (say, by the Centaurs?)

--Could it (alternatively) mark him as someone sworn to tell the 
truth?

--Or could it figure as a reminder to Harry, if/when he is 
particularly tempted to lie about something important?

I think there's a good chance that JKR will allude to it somehow, 
since, as DD says, "Scars can come in handy."