The Microsoft Manual of Style for Technical Publications

面白いです。例を幾つか紹介します。まずはcanとmayの使い分け。

can vs. may
Use the verb can to describe actions or tasks that the user or program is able to do. Use may or might only to express possibility or when the result of an action is unknown or variable, not to imply that the user has permission to do something.

次は"You"の説明。

Second Person
In general, use the second person (you) in most product documentation to refer to the user. Using the second person focuses the discussion on the user and makes it easier to avoid the passive voice....

ここまではよくある話。この続きが面白い。

Avoid writing error messages in the second person; by making the user the subject, it can sound as if the user is being blamed for the error.
Correct
The printer on LPT1 is not responding.

ここからダウンロードできました。