Chapter 4. Definitions

For the purposes of this document, the following definitions, as specified in the ISO/IEC Directives, Part 2, 2001, 4th Edition, apply:

can 

be able to; there is a possibility of; it is possible to

cannot 

be unable to; there is no possibility of; it is not possible to

may 

is permitted; is allowed; is permissible

need not 

it is not required that; no...is required

shall 

is to; is required to; it is required that; has to; only...is permitted; it is necessary

shall not 

is not allowed [permitted] [acceptable] [permissible]; is required to be not; is required that...be not; is not to be

should 

it is recommended that; ought to

should not 

it is not recommended that; ought not to