> ## Documentation Index
> Fetch the complete documentation index at: https://docs.joinmassive.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What are the rules for combining parameters?

When combining targeting parameters:

1. Mandatory Requirements:
   * Country parameter is always required
   * Additional parameters must be valid for the specified country

2. Parameter Hierarchy:
   * ZIP/Postal code takes precedence over city
   * Subdivision and city must match when both are used

3. Impact Considerations:
   * More specific targeting reduces available proxy nodes
   * Start with broad parameters and narrow as needed