# Workflow Automation: Using Filters

After we've set up a **Trigger** to begin the flow, we need to determine what "conditions" must be met in order to proceed (if any), before we can run any **Actions** step. These "conditions" are your **Filters**.

1. **Field Changed**

Check if a specific Podio Item *Field* has just been changed in value. **This is an important step in Update Flows**

1. **Field Value Match**

Match a Podio Item *Field* to a specific value (eg status='new')

1. **Field Previous Value Match**

Match a Podio Item *Field's* previous value to a specific value (eg status was 'new').

1. **Creator / Editor**

Check who created this revision in Podio that triggered this flow.

1. **Custom (Calc)**

When none of the above fit - Use a custom evaluation function in PHP notation.

1. **Date Match** - *By Date or Day trigger type flows only*

Match a specific date, day of the week or day of the month.

1. **Comment Match** - *New Comment trigger type flows only*

Check the contents of a triggering comment.

1. **Email Subject Match** - *Email Reply trigger type flows only*

Check the contents of an Email Subject line.