If you are looking for the DS1086LU EconOscillator clock generator IC from Maxim, you will see some part numbers with additional three-digits suffixes listed, such as DS1086LU-533+.
Per Maxim, the device base part number with the three digit suffixes are custom programmed frequencies. These frequency settings of these part numbers were locked so that they cannot be inadvertently changed.
If you need to program the DS1086LU devices yourself, then you should only order the DS1086LU+ (Tube) or DS1086LU+T (Tape and Reel). These variations are not custom programmed and the DAC and Prescaler registers are not locked.
Applicable part numbers
DS1086LU+
DS1086LU+C66
DS1086LU+T
DS1086LU-12F
DS1086LU-12F/T&R
DS1086LU-12F+T
DS1086LU-21D+
DS1086LU-222+
DS1086LU-222+T
DS1086LU-440/V+
DS1086LU-440/V+
DS1086LU-440/V+T
DS1086LU-440+T
DS1086LU-455/T+W
DS1086LU-455+
DS1086LU-455+
DS1086LU-455+T
DS1086LU-527+
DS1086LU-527+T
DS1086LU-533+
DS1086LU-533+T
DS1086LU-533+W
DS1086LU-834+
DS1086LU-8CL
DS1086LU-8CL
DS1086LU-8CL/T
DS1086LU-A12+
DS1086LU-B66+
DS1086LU-B66+
DS1086LU-B66+T
DS1086LU-C01+
DS1086LU-C01+
DS1086LU-C01+T
DS1086LU-C02+
DS1086LU-C02+T
DS1086LU-CCJ
DS1086LU-CCJ/T
DS1086LU±ND
DS1086LU+C66-ND
DS1086LU+TTR-ND,DS1086LU+TCT-ND,DS1086LU+TDKR-ND
2156-DS1086LU-12F-ND
DS1086LU-12F/T&R-ND
DS1086LU-12F+T-ND
2156-DS1086LU-21D±ND
DS1086LU-222±ND
DS1086LU-222+T-ND
2156-DS1086LU-440/V±ND
DS1086LU-440/V±ND
DS1086LU-440/V+T-ND
175-DS1086LU-440+TTR-ND
DS1086LU-455/T+W-ND
2156-DS1086LU-455±ND
DS1086LU-455±ND
DS1086LU-455+T-ND
2156-DS1086LU-527±ND
DS1086LU-527+T-ND
DS1086LU-533±ND
DS1086LU-533+T-ND
DS1086LU-533+W-ND
DS1086LU-834±ND
2156-DS1086LU-8CL-MA-ND
DS1086LU-8CL-ND
DS1086LU-8CL/T-ND
2156-DS1086LU-A12±ND
2156-DS1086LU-B66±MA-ND
DS1086LU-B66±ND
DS1086LU-B66+T-ND
2156-DS1086LU-C01±MA-ND
DS1086LU-C01±ND
DS1086LU-C01+T-ND
DS1086LU-C02±ND
DS1086LU-C02+T-ND
2156-DS1086LU-CCJ-ND
2156-DS1086LU-CCJ/T-ND