> ## Documentation Index > Fetch the complete documentation index at: https://docs.pingtree.com/llms.txt > Use this file to discover all available pages before exploring further. # Database Source Suppression > Prevent duplicate or DNC leads by matching field values against an internal lead database. > **Note:** This tab is available in **Custom Source (CS)**, **Marketing Partner (MP)**, and **Media Channel (MC)** source types. All Sources The **Database Source Suppression** tab allows you to block or reject incoming leads based on existing records in a connected **Database Source**. ### How It Works In Pingtree, a **[Database Source](/guides/database/database-source)** is separate from campaign-level sources. A campaign is linked to a DB source, where all collected lead data is stored. You can also upload leads directly into the DB source — independent of the campaign flow — and use that data for suppression or lookup purposes. This tab enables you to define suppression rules for an individual traffic source by matching incoming lead fields against the DB source. ### Suppression Field You can configure Pingtree to check a specific field (e.g., `mobile`, `email`, etc.). Every incoming lead will be evaluated against the selected field’s value in the chosen DB source. If a match is found, the lead will be **rejected**. ### Timeframe (In Days) You can choose to set a **Timeframe (in days)** to define how long a suppressed lead remains blocked: * If set to `90`, the same lead won't be accepted again within 90 days. After 90 days, the lead is allowed again, and the suppression resets. * If set to `0`, **timeframe-based suppression is disabled**, and matching leads will be blocked **indefinitely**. ### Common Use Cases * **Deduplication**: Prevent duplicate submissions by blocking leads that already exist. * **DNC (Do Not Contact) Compliance**: Suppress leads with phone numbers or emails flagged in your DNC database. This suppression method helps maintain data quality, compliance, and improves overall lead performance. *** * [Click here to view Custom Source Single View pages](./Custom-Source-Single-View) * [Click here to view Marketing Partner Single View pages](./Marketing-Partner-Single-View) * [Click here to view Media Channel Single View pages](./Media-Channel-Single-View)