EPD tool to remove false ep target squares
Norm Pollock wrote:

This tool removes false "en passant" target squares from an "epd" file. These false target squares are useless notation because an ep capture is not possible.

As an example of a false ep target square, when the opening move e4 is made, a false ep target square is created at e3.

The above direct link will be available for a short time. Otherwise the tool can be downloaded from "40H-EPD" on my site (see www below).

False target squares make it difficult to locate duplicate epd records (such as with "epdList" from 40H-EPD). This is because there could be 2 epd records, one with a false target square, and one without a target square. They are duplicates of the same position.

A false target square does not affect the 3-fold repetition rule.