Terminology Usage in v2.1.0

[PhilPNguy]

As of v2.1.0,

• There is no usage of "MAY" or "OPTIONAL" at all when there are many parts of the standard that should have them to be clearer.

• "CONDITIONALLY REQUIRED" is used once and not defined. Either we define the entire phrase, define just the "CONDITIONALLY" word, or decide to rephrase the sentence to follow RFC2119 (and not add additional key words).

From "5.2.3.1.1. Custom metadata about images"

The following information is CONDITIONALLY REQUIRED for each image on the Director repository IF that image is encrypted:
- Information about filenames, hashes, and file size of the encrypted image.
- Information about the encryption method, and other relevant information–for example, a symmetric encryption key encrypted by the ECU’s asymmetric key could be included in the Director repository metadata.

[PhilPNguy]

Based on Ira's comments during 2023/08/01 meeting, uptane no longer uses "MAY" and "OPTIONAL" keywords.
Any optional requirements will just not contain the other keywords (SHALL & REQUIRED).