N.M. Stat. § 21-7-24
In the event the board of regents aforesaid should find it advisable to issue bonds under this act [21-7-13, 21-7-14, 21-7-16 to 21-7-25 NMSA 1978] in more than one series, or at different times, for any of the purposes aforesaid, then each series of said bonds shall be designated by the letter "A," "B" or in some other designation to the end that each series shall be kept separate, and all of the requirements of this act shall apply to and be faithfully followed, done and carried out as to each of said series; provided, however, that said board of regents shall not have power to issue bonds hereunder, the aggregate annual requirements for which to meet interest and principal, shall exceed the amount of the income from the permanent funds of said university received by the state treasurer for the fiscal year next preceding the date of the issuance of said bonds or any series thereof.
NMS § 21-7-24