Both components and pins, nets and buses can have attributes attached to them. Attributes are text in the format ”name=value”. For example, nets can be named using a ”netname=” attribute, and components can be named using a ”refdes=” attribute.

Attributes can also be added to a page without being attached to another object. These are called floating attributes, and are most commonly used in symbols. When a symbol is placed into a schematic page as a component, any floating attributes in the symbol become inherited attributes in the schematic.

In addition to the name and value, attributes have two visibility settings. The first controls whether the attribute as a whole is visible, and the second controls which parts of the attribute are shown (just the name, just the value, or both).

There are two ways to add/edit attributes: editing them individually, or using the “Edit Attributes” window.

To add a single attribute to a component, pin, net or bus, select the target object and use Add→Attribute…. This will display the “Single Attribute Editor” window. Enter a name and value, and set the desired visibility settings, then click OK to add the attribute. If you use Add→Attribute… without selecting any object, the created attribute will be floating.

To edit an individual attribute, select the attribute (not the object it's attached to) and use Edit→Edit… to display the “Single Attribute Editor” window again. To update the attribute after making your changes, click OK.

A more powerful alternative is to use the “Edit Attributes” window. To display the window, select a component, net, pin or bus, and use Edit→Edit….

The “Edit Attributes” window is divided into two parts. The upper part shows all of the attributes that are currently attached to the object, and the lower part allows you to add attributes in a similar fashion to the “Single Attribute Editor”. The window automatically updates when the selected object changes.

In the top part of the window, each row in the attribute list shows the name and value of an attribute, and its visibility settings (“Vis?” for overall visibility, and “N” and “V” for name and value visibility respectively). Left-click the name or value of an attribute to edit it, and press <Enter> or move the focus to another field to save your changes. To cancel your changes while editing the name or value of an attribute, press <Escape>.

To delete an attribute, right click on it and select Delete from the context menu.

If the Show inherited attributes checkbox is enabled, and a component is selected, any attributes inherited by the component from the symbol it was created from are also displayed, but cannot be edited. To add an editable copy of the inherited attribute to the component, right click on the attribute and select Promote from the context menu.

To change the visibility settings for several selected attributes at a time, use Attributes→Toggle Visibility, Attributes→Show Name, Attributes→Show Value, and Attributes→Show Both (which sets selected attributes to show both name and value).

You can also change the visibility of all attributes that begin with a particular prefix using Attributes→Hide Specific Text… and Attributes→Show Specific Text…. For example, you could enter “refdes=R” to hide all refdes attributes with values beginning with R.