Explain briefly the purpose of this page (Why it is useful to the community/reader). E.g. The purpose of this page is to clarify the understanding of the system logic and requirements in relation to.....
This is the main body of your WIKI Page where you talk through the system logic or behavior you are explaining. Use pictures to emphasize the points you are trying to make or to illustrate the transactions/selection screens/reports etc.
Same as the first section, this is also part of the main body of the WIKI. You can add as many sections as you require to make the information you are explaining as clear and simple to follow as possible.
Use this structure to help you compose your contributions for WIKI and at the same time will ensure spelling and grammar.