I agree with you the FNMA guidelines are set standards and they can add to them. Just like USPAP is a minimum standards and each state can add to them. The real problem that I have is that they will say that it does not meet FNMA guidelines so they can not loan on it. Take the bank that has a flag and star in it, for example they have there guidelines for lending that exceed FNMA's. However, if they reject a loan based on their guidelines they say that it is based upon FNMA guidelines. Seems that it is a lawsuit waiting to happen with them. This is directly from an underwriter that works there. Just like FNMA won't loan on more than 5 acres condition/quality houses. Where in FNMA guidelines states they will not loan on 5 acres or fair condition/quality houses. Remember the declining market do not check that yet it states right in FNMA that they will except this.
But enough ranting from me. I have found that it is best to find what guidelines they are using and go from there. And when they do state it is FNMA guidelines and you send them to their underwriter you get no response.