Multiselect - lifelike/countersheetsextension GitHub Wiki
A column header id-? is used for multiselection of parts to included in a counter.
The value in that column is parsed as a list of partial ids, separated by spaces, that are used to decide what subset of some parts to select to include on that counter. Each partial id will be prefixed with id- from the header to construct the full id to match with an id-attribute in the template.
What that means is that if the header says sym-? and the value in that column for a counter is inf arm then the two objects in the counter with id sym-inf and sym-arm will be included, but all other objects with an id that begins with sym- will be removed (for instance a sym-cav object would not be included). The object can be a group of objects.
Multiselect can always be replaced with multiple Option-columns. For instance the example above could instead be done by having three columns sym-inf?, sym-arm?, and sym-cav? and for the example counter the columns would have values y, y, n. If there is a very large number of possible values to use however multiselect is a good way to keep the spreadsheet smaller and easier to read, and new parts can be added to the template without having to add yet another header in the CSV.
For some uses of multiselect (or option) a better way can be to use Clones. That can make the template much less cluttered when the purpose is only to make one of many possible parts appear in the same location.