* @return MOD_RES_ALLOW to accept the tag with the value in 'value', MOD_RES_DENY to reject the tag and act as if it wasn't sent,
* MOD_RES_PASSTHRU to make no decision. If no hooks accept a tag, the tag is rejected.
* The default implementation returns MOD_RES_PASSTHRU.
*/
* @return MOD_RES_ALLOW to accept the tag with the value in 'value', MOD_RES_DENY to reject the tag and act as if it wasn't sent,
* MOD_RES_PASSTHRU to make no decision. If no hooks accept a tag, the tag is rejected.
* The default implementation returns MOD_RES_PASSTHRU.
*/