Hello
This is what I found on Wikipedia:
The Writing Rules specify restrictions on grammar and style usage. For example, they require writers to:
Restrict the length of noun clusters to no more than 3 words
Restrict sentence length to no more than 20 words (procedural sentences) or 25 words (descriptive sentences)
Restrict paragraphs to no more than 6 sentences (in descriptive text)
Avoid slang and jargon while allowing for specific terminology
Make instructions as specific as possible
Use articles such as "a/an" and "the" wherever possible
Use simple verb tenses (past, present, and future)
Use active voice
Do not use present participles or gerunds (unless part of a Technical Name)
Write sequential steps as separate sentences
Put commands first in warnings and cautions, with the exception of conditions
You can google for more