What's it with IATA fares and codes?
 

There are lots of questions about IATA fares and such. What's the reason why there is such an interest in IATA fares?

IAIAT codes are for travel agents. Why would travellers be interested in looking for IATA codes or fares?
IF IATA fares are "fam" rates, they are not mean for general public. If you are not a travel agent, you should not be using them.

In the specific cases of the thread where I've seen them discussed it generally has to do with travel allowance from a job posting back home. The employee is allowed up to the IATA rate for the city pair but they can go anywhere so they need to know what the allowance is to plan their trip.