* Does FH ever change GEDCOM index numbers?

[mcws]

I am making an databse application to index family letters. For my sins I am using MYSQL and PHP, but I need to import  my GEDCOM file which I maintain with FH.

What I am worrying about is how to make sure I can import into my application a new version of the GEDCOM when I update it with FH.

My question is, 'Under what circumstances will FH change the individual and family index nos, which are given in the following format in the GEDCOM file
0 @I1@ INDI
at the head of an individaul's record,
and
0 @F1@ FAM at the head of a family record?'

I realise if I delete a person using FH then renter the person, they are going to have a new index number. Are there any other circumstances to beware of?
Is there any better way than using this index number to link my application database to specific records being maintained in FH?

ID:1788

[NickWalker]

I think they only change if you use the 'Work with record identifiers' dialogue. There may be other ways but even so I am certain that they will never change unless you do something to force this to happen.