[GAP Forum] What does <[ [ 1, 1 ] ]|b*a^-1> mean

[Sopsku]

Dear Forum,

I am continuing my struggle to learn a bit about GAP. I formed the
octahedral group using three elements (altho this is not important to to
questions). I asked GAP for
gap> asg:=AllSubgroups(g);;
## Look at the elements for one of these subgroups
gap> Elements(asg[24]);
[ <identity ...>, a*c^-1, <[ [ 1, 1 ] ]|b*a^-1>, c^-1*b, 
  <[ [ 2, 1 ] ]|c*a^-1>, c*b^-1 ]

I do not understand the notation, such as, <[ [ 1, 1 ] ]|b*a^-1> 

I have tried searching through the GAP manuals and some tutorials with no
luck is seeing anything expect the rather obvious <identity ...> which is
defined in the manuals.

Thank you for any help!
    Sopsku