Backup Exec 2012 vs Backup of Active Directory

Hello,

All of my servers backup jobs are configured like this;

Friday = full backup to disk + backup to tape

monday to thursday = Incremental Backups to disk + differential backup to tape

In the backup options of my ADS server (under Microsoft Active Directory),  there is a "information comment" that says.    "Only full backups of Active Directory are allowed"

I know that the message is telling it all but does it means that even if Backup Exec let me configure an incremental backup job,  only the full backup job is actually usefull ?

Thanks for clarifying that for me.