*.sym Symbol files. The schematic and symbol file formats
are identical. gschem (or a text editor) is used to create symbol
files as well as schematics. Symbol files contain lines, circles,
boxes, arcs, pins, text, and attributes.
The naming convention for symbol files is: name-#.sym where:
- name is a text string which describes what the symbol
represents.
- -# is a dash and a number (like -1, -2
etc...) The number is used to allow for a symbols to have the
same name yet different contents. There might be multiple
representations for resistors so these symbols should be called:
resistor-1.sym, resistor-2.sym, and resister-3.sym.
- .sym is the symbol extension/suffix. It is important
the symbols have this extension.
The way of specifying hierarchy is by using the source= attribute.
Please see the master attribute document for info on this mechanism.
The hierarchy mechanism is still in heavy flux, so there might be
some more changes.