In the Schematic canvas, entering a lower case suffix, for example a period of **2u** in a PULSE source, the suffix is always converted into upper case in **Properties > Custom Attributes** => **2U** http://i.imgur.com/8pMQBwU.png If an attribute with an upper case suffix is just *clicked on without editing it*, in **Properties > Custom Attributes** then the suffix in the Schematic is updated to upper case. http://i.imgur.com/wwVhKhU.png Spice is case insensitive so the case change has no effect on the simulation. However, mixing cases looks untidy in the schematic and netlist. *Can suffixes stay in the case they are entered in? *