In becoming TSR moderators (of varying hierarchical status such as supermoderators, global moderators and minimods, further also forum assistants), users are supposed to set a good example for appropriate online behavior as a by-product of their ongoing conversations.
Source: wiktionary
I think the difference between a minimod and a helpful community member is all in the tone each one uses, as well as what SSM said above with staff being online or not.
Source: wiktionary
Gonna be using this thread as a reference for people from now on I reckon some quality takes on Minimodding and what is defined as "acceptable" by the community.
Source: wiktionary