GNU parted documentation

[Tommaso Cereghetti]

Hello

I'm referring me to your GNU parted documentation, paragraph Set
http://www.gnu.org/software/parted/manual/parted.html#set

I do not understand the goal of defining these flags. Is it just 
informative?

I have 3 hard drivers, every one with two partitions 1) ext4 /for 
/boot)  2) raid and everything works fine.

But for one hard drive I get:
Number  Start   End     Size    File system  Name  Flags
 1      1049kB  525MB   524MB   ext4
 2      525MB   3001GB  3000GB                     raid

And for the other the informations are lacking:
Number  Start   End     Size    File system  Name     Flags
 1      1049kB  525MB   524MB                primary
 2      525MB   3001GB  3000GB               primary

Thanks and regards,
Tommaso