I was little hasty last night when I wrote that post, so I jumped in just to say what guys above have said:
You can use whatever terms you like, but 5/3/1 has quite simple logic in it, which includes 3 different weeks with different intensities (and some auto regulation, if regular amraps are used). If you want to put it in terms of stress or accumulation etc. you should know that 3/5/1 is more commonly used week order nowadays. With this order the idea should be easy to grasp.
For extra volume 5/3/1 uses submaximal weights (FSL), use them so you don't need to fuck up the program.