Seems most modern players have an effect parameter memory for some of the effects, such as slides. If you run the effects 208, 200 and 200 across three cells it is often implied that one means slide by 8 for each of the three rows which does make sense since the 200 would do nothing otherwise.
According to "MOD player tutorial by FireLigth" ProTracker has memory for effects, just not for all of them. It seems that only effects 3xx, 4xx and 7xx have the parameter memory.
