one reader's take: you have the makings of a very good regex article here...
my quibbles: the editorial matter (re strict, warnings, etc) before you get to regex issues might well be split off -- perhaps multiple splits, as others have suggested. Seems to me that the title would be annoyingly misleading, otherwise.
As for your use of English -- you have used some constructs that vary from the forms used by those whose first language is "American English" but almost none (see first list item below) of them obstruct understanding or present any serious obstacle to "ease of reading."
coupla' specifics: (updates, 20050328 and new language suggestions below (waaay! far down))
- Has been addressed:
para 4: "lined out equally" might be more colloquially phrased "aligned vertically." (problem is that "lined out" is synonymous with "struck out.")
- Suggest you expand para 8 with some examples, explanations. Advising one to "RTFM" is sometimes all well and good, but in an article with a tutorial intent, it seems to me to verge on rudeness to the reader (and lest that be a mystery, because (1) it's a contraction for a phrase which uses a word offensive to some and (2, more important) TFM is extremely dense and sometimes -- depending on the reader's learning style -- difficult to absorb. You might consider offering links several choices of explanatory material including but not limited to Owl, Friedl, TFM and others (Yes, I'm one such and would love to find the "other" that sings to me.)
- repeated below
"syntaxis" ??? Unfamiliar, not found in a quick dictionary check. Suspect you intend "syntax."
- Suggested addition: brief discussion of the ephemeral character of $1 ... (ie, reset issues) $1 is mentioned in para 6.
Hope this is some help. Please, drive on with your good work! ++