Layers are specified in CIF in a command with syntax
L token;
The the token can be interpreted in two ways; as the name of a layer, or as an index into a layer table. For the second interpretation, the token must of course be an integer.
layer_index | Historic Name | Format |
---|---|---|
0 | none | L layer_name; |
1 | NCA | L layer_index; |
Of these, the first entry is most common. Xic can handle both of these interpretations (see 9.7).
If the indexing is selected for layers, the index will be 1-based, and correspond to the layers, left to right, in the layer table, i.e., the leftmost (lowest) layer in the layer table is designated index 1.