[Asterisk-Dev] Disable flash hook hold?

[Barton Hodges]

I didn't really have any luck with this question on the Asterisk
User's list, so I'm trying here where people are familiar with the
source (although I've contributed a few tiny patches myself, this one
has me stumped).  Is there a way to completely disable putting a user
on hold when I briefly press the flash hook on the phone?  I would
like the phone to hangup at that time, no matter what.  I disabled
threewaycalling that is supposed to control this, but it doesn't make
any difference:  "threewaycalling: If enabled, you can place a call on
hold by pressing a hook flash, whereupon you get a dialrecall tone and
can make another call. Default: no."

I tried modifying wink, prewink, etc. but I could never get it
disabled.  Is there a place where "prewink", "preflash", "rxwink",
etc. are fully documented besides just "Pre-wink time (default 50ms)"?
I'd like to know what they actually do.

Thank you for any help at all,

Barton