What is the difference between a rule and a requirement? Can these words be used interchangeable in a national standard?
a principle or regulation governing conduct, action, procedure, arrangement, etc.
that which is required; a thing demanded or obligatory
Rules define things that either must, or must not be done, in order to to stay within guidelines.
Requirements define things that either must, or must not be done, to come within guidelines.
Rules are generally laws or regulations that you must follow, while requirements are generally some stipulation that must be met. Rules are followed, requirements are met.
You must follow the rule "no running" at the pool or you will be kicked out.
You must meet the requirement "swimwear required" to be permitted to enter the pool.
Rules must be followed to avoid possible punishment, while requirements must be met to be permitted to do some action.
All rules must be followed to stay within guidelines.
All requirements must be met to come within guidelines.
If one rule is broken, you are no longer within guidelines.
If one requirement is not met, you are not within guidelines.
If one rule is followed, nothing changes. You still have to follow each rule.
If one requirement is met, nothing changes. You still have to meet each requirement.
The two words are not directly interchangeable. But, you can change some wording very slightly to exchange the two words and keep the same meaning.
Context: A class syllabus, possibly.
Original rule: You must not cheat on the test, or you will fail.
Exchanged: You must not cheat on the test to be able to pass.
Explanation - "No cheating" is a rule for the class and it is punishable by failure. It could therefore be considered a requirement for passing the class.
This does not mean that you should exchange the two words though. Rules are generally used when describing how to maintain eligible status, while requirements are used when describing how to achieve eligible status.