I have used "¬" as a parameter in Script Parsing for 7 + years to script a tree process through to a desired result.
"¬" has worked as recgonised and undeclared value in both the Mac & Win environment from ".fp7" up thru FM 15's ".fmp12" as far as I can tell.
I had thought "¬" worked until I caught its failure in FM 16 when I ran script debugger.
Pre FMP 16: typical Script Parameter passed to Called TO's ID if TO's called ID is not known Thus :
If Known TO::ID:
"LayoutName|Navigate|Form|" & TO::ToID
Else If unKnown TO::ID:
Parsed Script Parameter "¬" produced an extractable ID
"¬" should be available as $SP 
There has been major discussions over the years about legitimate usable characters: Upper & Lower case alphas "a" thru "z" and numbers 1 thru 0 with Underscore as the primary characters allowed.
With FMP 16 there are now other known (FMP 15) usable characters that have been moved to the unusable column.
This without a know posted list of deprecated characters.
At this point I am flying blind. Do I wait for v.1 in hopes of fix or do I bite the bullet and expend unnumberable hours revising "¬" to a specified <unknown> value at this point through out.
I would like to know how many other characters such as "¬" are now no longer recognizable & will produce false results and should be avoided.
Currently this is a Major time hurt.