I found this...

"The symbols used on schematic diagrams for the various types of switches discussed above were shown in Figure 1, which was with Part 1 of this series of articles. Schematics often used abbreviated terminology such as NO, SPDT, etc. mentioned earlier. Often the abbreviations 'OWE' (open when energized) and 'CWE' (closed when energized) were used next to switch symbols This was normally used when a switch was operated by a solenoid coil, 'energized' referring to the condition where that coil had current applied to it The terms 'OWI' (open when in) and "CWF (closed when in) were used to refer to switches operated by the movable 'shuffle panel.' found on older games, which moves 'in' when the coin chute was pushed in at the start of a new game."

...at this site http://www.pinballcollectorsresource.com/russ_files/trouble51.html

Maybe there's more at the site, I didn't read the whole thing but OWI (open when in) so maybe CWI is closed when in. Henry

And is CWF a typo that really should be CWI - just what you're looking for1