Solution:

You can get a sheet of black labels, or with letters or with numbers. Here is the datasheet with the labels (all the part numbers with MT5xxx will work with the ER2.5 terminals. http://www.bb-elec.com/Products/Datasheets/MT5_MT10_TBLabels-3106ds.pdf For example the part number MT5 is 500 pieces, all blank, the MT5-0 is 500 pieces with 0 on them, the MT5-1-50 is 500 pieces marked 1-50 (1, 2, 3, etc..50) The MT-A is 500 pieces all A. You can also get a group label (GM and GM2 shown above) See pic below for labeling example: