EXHIBIT OR CONCESSION LIMITATIONS. The Licensor has the right to prescribe the materials to be used in the construction of booths, signs, show cards or tabloids of exhibits and to regulate their dimensions and positions, and generally direct the arrangements of articles exhibited so far as the same may be necessary to secure an attractive appearance. The licensee must confirm all exhibit activities to within the limits of the space allocated to it. No soliciting or advertising for any purpose will be permitted on the grounds except from within the space for that purpose.