Most pattern books I have seen will be written in one form, with a conversion table at the front. Sometimes a pattern wont specify, but you can work it out if there is an illustration, or by some of the terminology (if there is a hdc its US, if there is a htr its UK)
Patterns can be confusing and wordy, and I will do my best not to confuse the subject any further!
I made a couple of conversion charts, feel free to pin or save for later! I will also have them over in my Stitch Library (click on the button to the right to find it)