ignore local change

Dear list,

version: subversion 1.6.6 on cygwin, FC12 and also tortoise svn.

I have some local changes that I want to keep, and wish they did not show
up in svn status.

For example,
on production
         mail = "#users_real_email#"
on dev machine
         mail = "#fake_email_for_debugging#"

I want subversion to ignore this difference when I do "svn status"
locally.

< mail = "#users_real_email#"

---
> mail = "#fake_email_for_debugging#"
But if there are other changes except for this, I want them to show upon
"svn status".
There is a need to change the file from time to time, so I don't want to 
put the whole file in svn:ignore list.
Is there a feature in subversion or subversion-perl that allows me to let
subversion "ignore" only certain differences within a file?
Thanks.
Ben Kim