Special $'s

(Merge only) There are two special variables. Often auxiliary collateral needed by Merge is located relative to the supplied form file or data file. So...

$$F

$$F means the folder where the form specified by -form is. (or first form if a form list is being used). Note that it is not 'the folder where forms are usually kept', but is rather more specific, referring to the folder where the form is for this run of Merge. If DocOriginCombineForms is used, resulting in a temporary form file, that has no bearing, $$F will be the folder used/implied in the -form parameter.

$$D

$$D means the folder where the data specified by -data is. Running filters which create temporary versions of the data file have no bearing, $$D will be the folder used/implied in the -data parameter.

These have no connection with, are not at all intertwined with $F or $D, whatever they might be. These are two, independent, special variables.

It is possible to say -data $$F/../data/xxx.xml. That is, you can define $$D by using $$F.

(FilterEditor only) There is one special variable.

$$X

$$X means where the .xfilter file is. $$X occurs inside .xfilter files. Its use makes .xfilter files and their related collateral more portable, e.g. for support requests or sharing with other team members.