# Data Flow Matchers (/docs/consent-management/reference/telemetry-and-data-flows/data-flow-matchers)

Data flows are request matchers that can be used to assign tracking purposes onto matching requests.

## Host Matchers [#host-matchers]

These are hosts, such as `example.com` and `[::1]`. The data flow creation dialog automatically extracts hosts from any absolute or any-protocol URL.

## Path Matchers [#path-matchers]

These are full or partial URL paths. The following examples show the allowed formats:

- Absolute: `https://example.com/path/to/resource`
- Any-protocol: `//www.example.com/path/to/resource`
- Same-site: `/path/to/resource` or `path/to/resource` (this only matches for requests to the same site as the current page)
- Any-site: `///path/to/resource`

Note: Absolute Path matchers using the `data:` URI scheme are not supported at this time.

## Query Parameter Matchers [#query-parameter-matchers]

These are URL query parameters, such as `?utm_source`. Value constraints can be added to matchers, such as `?utm_source=example`, which will match requests that have the query parameter `utm_source` starting with the value `example`.

## Regular Expression Matchers [#regular-expression-matchers]

These matchers can be used to match any part of a request, and are applied against full URLs. An example of a regular expression matcher is `^https?://example\.com/path/to/resource`, which will match requests starting with `https://example.com/path/to/resource` or `http://example.com/path/to/resource`. Note that Regular Expression matchers can have significant performance impact, so be sure to test the performance impact on your site when adding many of these matchers.