Aux belt (?)

[sipar69]

Betraying my lack of technical knowledge here.....
 

Took my Z for a service last week.  Although this wasn’t an MOT I noticed when I got home that the garage jotted down a couple of what they said were minor advisories.  One was “Aux belt looks old but not cracked”.  I had my drive belt replaced at the last service so is the “Aux belt” something different? 
 

Cheers  

[ZMANALEX]

There is only one belt.

[sipar69]

Cheers Alex.