Feature templates define all the information required to create a feature: the layer where a feature is stored, the attributes a feature is created with, and the default tool used to create the feature. Additionally, new data with a new category can be added to the attribute table of a feature layer by using a feature template.
The following instructions describe how to add a new category in a feature template.
In ArcMap, start an edit session.
Open the Create Features window by clicking the Create Features button.
Open the Organize Feature Templates window by clicking the Organize Templates button.
Click either New Template or Copy to create a template based on the existing layer.
Double-click the new template. This opens the Template Properties dialog box.
Edit the properties of the template, and click OK.
Right-click the layer name in the Table Of Contents > Properties > Symbology tab.
Click Categories, and click Add Values. Type a new value, and click Add to List. Click OK.
Change the symbology of the new value as desired by double-clicking the new value. This opens the Symbol Selector dialog box.
In the Layer Properties dialog box, click OK. A new category is added in the feature template. Create new features using the new template.