I believe it's addressed in the EXCLUSIVITY clause in Section IV.B. as follows:
i. East of The Mississippi - any other theme park is limited to using characters not currently being used by MCA at the time such other license is granted. [For purpose of this subsection and subsection iv, a character is “being used by MCA” if (x) it or another character of the same “family” (e.g., any member of THE FANTASTIC FOUR, THE AVENGERS or villains associated with a hero being used) is more than an incidental element of an attraction, is presented as a costumed character, or is more than an incidental element of the theming of a retail store or food facility; and, (y) in addition, if such character or another character from the same “family” is an element in any MCA marketing during the previous year. Any character who is only used as a costume character will not be considered to be “being used by MCA” unless it appears as more than an incidental element in MCA’s marketing.]
ii. West of The Mississippi - any other theme park may use any Marvel characters whether or not used by MCA.
iii. East or West of The Mississippi - permitted uses shall be limited to the use of specific Marvel characters and Marvel may not permit a licensee to use the name “Marvel” as part of the attraction name or marketing.
iv. East or West of The Mississippi - The foregoing permitted uses will be subject to the following marketing restrictions:
(a) If the particular character is used by MCA (as defined above), such character will not be advertised or promoted East of The Mississippi, except by means of national Network buys of television, within printed materials such as brochures, or by print advertisements in periodicals directed to readers more than 300 miles from Orlando; and with regard to any of the foregoing permitted marketing, if the marketing is for a group of theme parks located both East and West of The Mississippi, the marketing shall make abundantly clear that the character only appears in the parks West of The Mississippi and shall not be subject to confusion on such point (such as would occur by visual inclusion of the character in a generic, multipark advertisement subject to a small print explanation of the parks where the character is present).