Std Gold Corp rate can usually be given by IHG globally to most companies over a certain size that contract to book more than nnnn nights per year worldwide. (HH. MR etc do similar corp program)

Separately the bigger companies eg HP. IBM etc negotiate globally for better deal, plus some local deals where they have presence leading to higher room numbers needed.

Sometimes I get to see 2x corp rates , one higher, one lower priced, but after certain number of rooms booked in hotels ie hotel occupancy > nn percent, I can only get the higher priced corp rate. Sometimes rates are just higher %age off rate at time we book, sometimes a simpler low fixed rate per night, which can be massive discount if booking late in when hotel is at highish occupancy with just the higher last miniute flex rates on sale.

Even so a few hotels near main offices, with our corp discount negotiated locally direct with individual hotels, then corp rate may even apply to an hotels last available room.... which doesn't happen with corp gold or similar.