Inappropriate tone can hinder reader access to information. A neutral tone free of opinion or personal flavor reduces the processing load for the reader to understand the information. Another benefit of a neutral tone is that several writers can work in parallel on a large technical documentation project. Furthermore, different writers can join the project at different times. The use of a neutral tone helps to achieve consistency across a documentation set, and thereby facilitates user access to information. The best way to achieve a common, neutral tone is to apply the following principles:
Humor distracts from the information you are trying to provide. Humor also makes documentation difficult to translate. Stay factual.
Whether you think a function is useful or woeful is irrelevant. Report the function to the user, with instructions about how to use the function. Stay accurate.
Colloquial language is difficult to translate and usually culture-specific. Stay neutral.
An expression that is in common use today might convey something completely different tomorrow. Stay technical.
Statements about the future developments of a product do not belong in technical documentation. Write about what you see right now. Stay real.