In a PCB, each component is identified by a reference consisting of a code and a serial number. The abbreviation (R, C, U, etc.) specifies the type of component, while the sequence number (R1, R2, etc.) identifies each individual component. The operation of assigning a reference to components can be both manual and automatic.

The automatic numbering operation of the components assigns a unique reference to all components of the PCB. You can only number some components that do not have a valid reference (references with?).


Select one of the available numbering operations.

Annotate all devices

This operation numbers all components starting with 1.

Annotate only devices with ?

This operation numbers only the components to which corresponds a reference containing the character ? (R?, C? etc.). Components that have already been numbered are not changed.

Clear all references

This operation resets all references by inserting the ? character instead of the sequence number.

Apply to the following

Specify the types of components to be numbered.


You can update the references of all components of the PCB or only those on the specified side.


You can specify the numbering order among those listed in the box.


This box lists some options. To activate them, click on the line to activate the check mark.

Create report

A document is created indicating the changes made.

Distinct numbering for each side

A separate numbering is performed for each side of the card.

See also