HTTPS details in TAXII

All,
In Section 2 of the specification we talk about Transport requirements and some of the encryption requirements for implementing TAXII over HTTPS..  I have a question / concern about one of the requirements that we have listed.  It says:
TAXII Servers and Clients
MUST
implement TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 [RFC5289] and
MUST NOT
offer or negotiate (bid down) an encrypted connection with parameters weaker than TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384.
We have heard from a few people that they do not understand what is meant by "weaker than". There is a concern that  people that are not super familiar with Crypto will get this wrong. So I am wondering if we can just be silent about this. As such I would like to propose that we just remove that requirement from the specification.
Bret