SMPTE AG-04, Clause 2 specifies the following re the use of "may":
The following keywords have a specific meaning in the context of this document:
- shall and shall not express a requirement from which no deviation is permitted;
- should and should not express a strong recommendation without necessarily mentioning or excluding other choices;
- may expresses explicit liberty (or opportunity) to do something;
- Note and informative indicates that the associated prose is not indispensable, and can be removed, changed, or added editorially without affecting the scope, or the document's usage.
ISO specifies the use of "may" as follows:
ISO specifically prohibits the use of "may" for any purpose other than permission.
They specify other terms for ability/lack of ability/opportunity/lack of opportunity:
The go even further, defining how to express external constraints:
I do not have any objection to using "might" in a non-normative statement.
It is important to clarify the use of "may", as it is not to be used in the place of "can" or "might". There shall be no room for interpretation.
And, the converse of "may", i.e., "may not", is actually "shall not".
This boils it down:
SMPTE AG-04, Clause 2 specifies the following re the use of "may":
The following keywords have a specific meaning in the context of this document:
ISO specifies the use of "may" as follows:
ISO specifically prohibits the use of "may" for any purpose other than permission.
They specify other terms for ability/lack of ability/opportunity/lack of opportunity:
The go even further, defining how to express external constraints:
I do not have any objection to using "might" in a non-normative statement.
It is important to clarify the use of "may", as it is not to be used in the place of "can" or "might". There shall be no room for interpretation.
And, the converse of "may", i.e., "may not", is actually "shall not".
This boils it down:
