Slides adapted from version by Dr. Michele C. Weigle
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.
Note that the force of these words is modified by the requirement level of the document in which they are used.
1. MUST This word, or the terms "REQUIRED" or "SHALL", mean that the definition is an absolute requirement of the specification.
2. MUST NOT This phrase, or the phrase "SHALL NOT", mean that the definition is an absolute prohibition of the specification.
3. SHOULD This word, or the adjective "RECOMMENDED", mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.
4. SHOULD NOT This phrase, or the phrase "NOT RECOMMENDED" mean that there may exist valid reasons in particular circumstances when the particular behavior is acceptable or even useful, but the full implications should be understood and the case carefully weighed before implementing any behavior described with this label.
5. MAY This word, or the adjective "OPTIONAL", mean that an item is truly optional. One vendor may choose to include the item because a particular marketplace requires it or because the vendor feels that it enhances the product while another vendor may omit the same item. An implementation which does not include a particular option MUST be prepared to interoperate with another implementation which does include the option, though perhaps with reduced functionality. In the same vein an implementation which does include a particular option MUST be prepared to interoperate with another implementation which does not include the option (except, of course, for the feature the option provides.)
foo://username:firstname.lastname@example.org:8042/over/there/index.dtb?type=animal&name=narwhal#nose \_/ \_______________/ \_________/ \__/ \___/ \_/ \______________________/ \__/ | | | | | | | | | userinfo host port | | query fragment | \________________________________/\_____________|____|/ \__/ \__/ scheme | | | | | | name authority | | | | | | path | | interpretable as keys | | | | \_______________________________________________|____|/ \____/ \_____/ | | | | | | scheme hierarchical part | | interpretable as values name | | | path interpretable as filename | | ___________|____________ | / \ / \ | urn:example:animal:ferret:nose interpretable as extension path _________|________ scheme / \ name userinfo hostname query _|__ ___|__ ____|____ _____|_____ / \ / \ / \ / \ mailto:email@example.com?subject=Topic
The tools we have to solve the interoperability problems are Resource, URI, and Representation
GETrequest to www.cs.odu.edu
$ curl -iv http://www.cs.odu.edu/~mkelly/
from S. Alam "Support for Various HTTP Methods on the Web"