Web-pages does not have limit in size of page like newspapers or limit in time like TV-shows.
- keep it short; the shorter article will be - more people will read it
- keep it simple; pretend you're speaking to someone who's smart and competent, but doesn't know technical jargon and may not speak English very well. Use short words, active verbs, and common nouns
- put the most important thing first; the first two words should include at least a taste of the most important information in the string
- describe only what's necessary, and no more; don't try to explain subtle differences. They will be lost on most users
- emphesize main things; like in this sentence
- Worst: The passive voice should be avoided.
- Bad: The passive voice should be avoided by writers.
- Better: Writers should avoid using passive voice.
- Best: Writers should use active voice.
As a result, readers don't have to jump through as many cognitive hoops when trying to understand what's going on.
For the same reason, it's usually better to write a positive statement ("do X") than a negative statement ("avoid Y"), and it's almost always horrible to use double negatives ("avoid not doing X"). Again, the simpler the translation between the text and the user's mental model, the easier the writing is to understand.