An Extended Position Description file is a text file with chess positions;
each having some associated text.
Like PGN, it is a common standard for chess information.
EPD files contain Opcodes , or fields, which are separated by semicolons in the file, but shown on separate lines in Scid's EPD Window. (Semicolons within an EPD field are stored as "\s" to distinguish them from end-of-field markers). They have a number of uses. Scid uses an EPD file to classify games according to the ECO system, and you can create an EPD file for your opening repertoire, adding comments for positions you regularly reach in games [Feature removed].
At most four EPD files can be open at any time.
Scid vs PC will automatically save changes to all EPD positions on the fly. To avoid dataloss, please backup EPD files before using them.
To browse the positions in an EPD file, use the Control+Down, Control+Up, Control+Home or Control+End keys. These commands move to the next/previous position in the file, clearing the current game and setting its start position.
EPD files can be automatically annotated by the Tools--> Annotate Positions menu. A dialogue will ask for the Analysis Time , and the first analysis engine will start. The EPD tags used are acd, acn, ce and pv.
EPD files you find on the Internet may contain fields that do not interest you, and they can waste a lot of space in the file. For example, an EPD file of computer evaluations might have ce, acd, acn, pm, pv and id fields but you may only need the ce and pv fields.
You can strip out an EPD opcode from all positions in the EPD file using the Tools--> Strip out EPD field menu.
The status bar of each EPD window shows: