After re-reading your request I regret that NX is aware of the issue and NX 7.5 has not yet implemented a way to communicate in that way between the Custom symbol library and the annotation editor.
The preferred solution is to locate it as needed, which can be rather time consuming.
It is...
Theses may be two different issues.
1. Symbol font aka where you access your flagnotes from the utility directory.
2. Custom Symbols, which will reside with you, not our servers.
Custom Symbols can be accessed in the same way by going to Note - text input - symbols - category - custom symbol...
Logan, Thanks for bringing this to our attention.
In response to your inquiry about Symbol Fonts,
The Symbol font are captured under the same directory as your local UGII folder, but only when running native NX. Here you will find ug_default.sbf.
However when NX is accessed through Teamcenter...