Navigate to Feed Tool > Feed Rules.

To start to create a rule, first select your desired Custom Label attribute from the drop down menu at the top, then click Add Rule to access the Edit Rule Panel:

Next, click Add Rule in the panel directly below:

Scroll down to the Edit Rule section to reach the builder.

This determines the type of rule you'll be using to edit your attribute and modify products. There are currently 4 Rule Types that can be built depending on the attribute you select.

For Custom Labels 0-4, you will most likely want to use Text Attribute Builder combined with Custom Text.

Start by clicking on the gray drop down field in the text string area, and then select an attribute you wish to add to the string. Utilizing the Custom Text field, enter the desired name of your Custom Label:

Build filters to ensure your modifications are only applied to products that match your criteria. By not creating a filter, you are enabling a rule to apply to ALL PRODUCTS in your feed. Filters can consist of single attribute criteria or multi-attribute criteria by clicking Add Filter to build each additional criteria desired:

Filters can differ by their function using AND / OR logic. To create an OR logic, a filter must have multiple values entered at once:

To create AND logic, there must be multiple filters that all determine the select criteria:

Use this section to determine which channels you wish to have rules applied to. Simply check off your desired channels and uncheck those you do not wish to apply rules to:

Note that your channels will also be listed on the rule itself:

Once you are satisfied with your modifications, you will have to save your rule:

Scroll down to preview the changes under Selected Rule Preview. Note that if you are unsatisfied with your rule or made a mistake in your set up, you can return to Edit Rule to adjust at any time:

All column headers are filterable using the filter icon to the right of the column name. You can adjust which columns are displayed by clicking on the three-bar icon to at the top right corner:

Additionally, you can export the entire table into a CSV file using the export icon:

To ensure your modifications take affect, you will have to send your feed to your respective channels. Do so by navigating to API Feeds > Send Feed:

Note that you will have to send each channel feed separately if you are currently linked to more than one channel.

Also note that average processing times vary from channel to channel with Google and Microsoft Bing taking up to 2hrs or more to show changes while Facebook may show changes within minutes.