[otrs] Changing Ticket Handle After Going Live

We've been using OTRS 3 as our live ticketing system for a few weeks now and I've started to notice that the ticket hook we use isn't descriptive enough. It gets confusing when we forward a ticket out to a vendor and then a second ticket number is added. Does anyone know offhand if it will break "replyability" to existing tickets if we change that in sysconfig? For example, today we use: RE: [Ticket:2010110110000378] Unable to access ECD and ECQ I would like to change that sysconfig option to XYZ-Ticket If I do so, will email replies (with the old hook) still be merged back into the old ticket? Hugh