portref. Using "bic" is good for input ports on symetric devices. Using "boc" is good for the outputs.
For DC/RF pads the "bcc" is a likely candidate.

Allowing shapes to relate to ports saves a lot of equations being re-used and thus makes the file more readable. An example is the polar bend, where the end point is [R*cos(a),R*sin(a)] so if you need to define a small rectangle on the "inside" of the bend, you need lots of equations.
The alignment values are shown below and refer to a rectangle that will fit just around the shape you work on; so for a circle the bil will not be on the bic location but at [-R,R] compared to the center of such a circle.
|bil     bcl    bol|
|                  |
|bic     bcc    boc|
|                  |
|bir     bcr    bor|


This element is simple - it does not have attributes or elements. The text that fills up the ... is value used.

<pdaShapeAlign> ... </pdaShapeAlign>


The schema file can be downloaded or viewed at xPDK_Base.


Type pdaIdentifier

Identifiers are used in the Python library for the getName() and setName() function and can thus be used to identify the different elements in list s.
In text the specification is a letter, followed by letters, numbers, underscore or dot. The XSD schema validation is a regular expression: [A-Za-z]([A-Za-z0-9_])*