The order to follow is: Creative Commons < General Rules < Special rules on the deviation page < Written permission.
Which means that these rules override certain items of the Creative Commons license, and in turn, the rules stated in the deviation's description may override certain items of this document. Additionally, you may ask for special permissions in a note, but that will only apply to the item in question.
Lack of lingual skills (i.e. not speaking English) is not an excuse. You must fully understand the rules. If you do not understand something, have somebody else who is better at English translate it to you. Do NOT use Google Translate.
MMD: in this case, it also includes MMM.
Third-party application: any application that is not MMD, MMM, or one of their utilities.
Model: a complete character with body, face, hair, and optionally clothes.
Part: an item made specifically to be used as part of a model.