Okay, since it pops up pretty much every time Jiang Wei introduces himself, and it's not really the kind of thing I'd expect people to know about offhand, I feel like this would be good information to keep in here.
~*~A QUICK AND DIRTY GUIDE TO CHINESE STYLE NAMES~*~ as paraphrased from
kongming.net Style names don't really come up in the English-language releases of Dynasty Warriors games (they do in the Japanese voice track, from what I have heard so far), but if you read Romance of the Three Kingdoms they are goddamned everywhere. And way back when I first read it, I was like "wait, why do they keep calling Liu Bei 'Xuande'? *psyduck*"
Ye olde Chinese names have three parts. Surname and given name are self-explanatory (and come in that order; so Jiang Wei's family name is Jiang, not Wei).
But then you have the style, style name, or familiar name: whatever you want to call it, the idea is that someone's given name should be respected. You don't use it lightly, so instead you get a style name when you come of age; Jiang Wei's style name is Boyue.
Who uses it:
Peers would address a man by his style name.
Elders and superiors, however, may use his given name. They might use his style name anyway, if they choose (doing so de-emphasizes the difference in rank). (His father and grandfather, however, may not use his style name, and would just use his given name.)
Inferiors don't get to use his style name or his given name, because they'd be using his title and surname only.
This assumes you want to show respect. You don't have to use the style names of your enemies, since you aren't obligated to show them respect, but some will do so anyway, as a show of their own refinement and self-control.
Of course, most characters in camp don't know all this anyway (and social rank is hard to define in a cultural melting pot), so Boyue isn't exactly going to be reading what people call him as a sign of their own manners or lack thereof (castmates aside, of course). He'll just chalk it up to "foreigners, lol."
This is the basic gist of it. If you want a better, more thorough explanation, that also goes into how things work differently for the ladies, and the hilarity of emperors' names becoming taboo, there is a fabulous write-up
here, which was the source of all the information in this post!