ProCite is a reference management software program originally developed by Personal Bibliographic Software in 1983, it was discontinued in 2013 in favor of the software title EndNote currenty owned by Clarivate.
ProCite versions 1-3 used a database system of files with extensions, .DAT, .PMT, .REC, .SRT, .KEY, .OUT, .LST, & .FRM.
ProCite versions 4+ used database extensions, .PDT and index file .PDX. Along with Output Styles .POS, Term Lists/Journal Lists .PJL, and Workforms .PWF.
.PDT and some .DAT files begin with hex values "
B4 F4 5C 00 0C C1 9A 00"
ProCite .PDT files can be opened with Endnote X1 and saved as EndNote .ENL file.