In the 2007 USSF memorandum, there appears to be a conflict with the wording in the advice to the referees and the text of the 2007 FIFA LOTG. This is in regards to an undergarment worn under the shirt.
The text of the LOTG states: a jersey or shirt – if undergarments are worn, the color of the sleeve should be the same main color as the sleeve of the jersey or shirt.
While the advice to the referees states: The general purpose of this change is to ensure that the visible color of any portion of a garment worn underneath the jersey or shorts is consistent with the main color of the jersey or shorts.
So, my question would be if a player has a blue jersey with white sleeves, does the undershirt have to be blue or white?
Answer (August 16, 2007):
We would refer to the “changes” you outline as minor adjustments in interpretation. The intention in Memorandum 2007 was to ensure that whatever extends beyond the uniform be seen as much as possible as an extension of the uniform. Note, for example, the language of the original restriction on undergarments (sliders, thermal/compression undershorts, etc.); they were required to be the same main color as the shorts. The Law didn’t say the same main color as the legs of the shorts, even though it is possible for the legs of the shorts to be a different color than the waist area of the shorts. The current language is an applicable generalization: Whatever part of the uniform the undergarment extends from is what the undergarment should match.
You might also remember that the Advice to Referees makes it quite clear that its contents may become out of date when new memoranda are issued by FIFA or the United States Soccer Federation.