Google can come in handy when trying to source a rule mentioned in your answer.
Unfortunately, Google isn't perfect, and some people don't bother to check whether they're using the latest version.
FIFA / IFAB
The old FIFA slideshows (this one is from 2004) uses easy-to-read bullet points, but the information is about 10 years old and lacks specifics.
FIFA also used a massive booklet (until 2015/2016) which documented every single point FIFA wanted to cover. Searching for specifics was a painful chore, but you got the right information.
As of June 1, 2016, new IFAB Laws of the Game have been released. It's now arranged in a neat, modern website which allows you to access the specific law you're looking for within a few clicks.
Need a diagram? Download the PDF of the law.
Not sure what you're looking for? There's a search bar now.
MLB
As of the 2015 version of MLB's Official Rules, many rule numbers have been revised from previously published versions.
The latest version of MLB's Official Rules can be found here.
Athletics
The IAAF's competition rules govern athletics ("track and field" in the USA, "light athletics" in some other languages) from 1 November 2015 through 2017. Notably, many protests, disqualifications, etc. in major competitions will not detail the infraction but only cite the rule number applied, e.g. "DQ Rule 163.3(a)" would indicate that an athlete was disqualified for stepping out of their lane during the race, and "DQ Rule 162.6" would indicate a false start.
Please use the new resource for information's sake and for your own. Thanks :)