XML allows profiled output (Score 1)

DocBook or DITA are two XML vocabularies designed to write technical documentation and procedures. Coupled with a CMS like Calenco (shameless plug), you can write procedures independently, and then gather them inside whole documents, in a modular and versatile way. Additionally, you can in the same procedure, tag chunks of information as being, for example, basic or expert information. Depending on your audience, you can then output documents in various formats (PDF, html, etc.) with the information directly relevant for your target.