Im looking for an OB/GYN and need some help with a question please?

Im looking on my hospitals website under find a physician and i type in obstertrics as the specialty. When a list of doctors come up it shows info on them and some of them it says there specialty is something differtent from an ob/gyn. but its still under the obstetricians search results. does this mean they are not obstetricians or is it just there OTHER specialty? Im confused.