There are many areas that are looked at in order to determine whether the candidate is ready or worthy to be asked into the Order of Chivarly. The main areas are:
Prowess is basically the skill in combat. Lochac tends to favour those who excell on the tourney field.
Renown means to be known throughout the Kingdom in a positive light. It could be that you give back to the fighting community, and definately your skills in fighting. If a member of the Order of Chivalry hasn't heard of the candidate's name, they will ask why they haven't heard of the person.