OFPEC Tags were originally introduced in 2002 as a way of avoiding conflicts between different addons. The system was so effective that it was officially adopted by BIS. Today, every respectable addon maker has their own individual tag.
An OFPEC tag is simply a three to five letter identifier that is individual to each designer. If an addon does not have a tag it could create a conflict with another addon: this may cause your mission (or even your whole computer) to crash. Additionally, scripts which make use of global variables should utilise tags so that global variables in other scripts don't conflict.
OFPEC tags should be used for all of the following:
- Global variables
- Global function names
- New classes (in config.cpp files)
- P3D names
- Addon PBO names
Tagged variables take the following format:
where the tag is upper-case and followed by an underscore. Tags can be made up of letters and numbers, but the first character must be a letter. The tag registration system ensures that your tag is valid and unique before submission, and will give instructions if you choose an invalid tag combination.
In Armed Assault, there is a method of verifying addon integrity through signed PBOs, which uses a key system. Jerry Hopper added the signed PBO keys into the OFPEC tag system so there is a central location for all keys.
If you intend to release addons for use within the Community, you should create a Public and Private key. Use the DSCreatekey.exe to generate this. Once you have your Public key, upload it to your OFPEC Tag account.
With the Private key you can sign your addons, and the Public keys can be downloaded by server owners to ensure addons are 100% genuine.