Reapply "Synthetics: document use-site variable filters ({{ var | filter }})"

layouts/shortcodes/synthetics-variables.en.md

@@ -26,4 +26,22 @@ To create a local variable, click **+ All steps > Variables**. You can select on
 {{ result-id }}
 : Injects the Result ID of your test run.
 
-To obfuscate local variable values in test results, select **Hide and obfuscate variable value**. Once you have defined the variable string, click **Add Variable**.
+To obfuscate local variable values in test results, select **Hide and obfuscate variable value**. After you have defined the variable string, click **Add Variable**.
+
+### Apply filters to variable values
+
+When you reference a variable, you can transform its resolved value by appending a filter with a pipe (`|`). Use the syntax {{ VARIABLE_NAME | filter }} anywhere a variable is accepted, such as the URL, request body, headers, and assertions. The following filters are available:
+
+{{ VARIABLE_NAME | urlEncode }}
+: URL-encodes the variable's value. For example, `hello world` becomes `hello%20world`.
+
+{{ VARIABLE_NAME | urlDecode }}
+: URL-decodes the variable's value. For example, `hello%20world` becomes `hello world`.
+
+{{ VARIABLE_NAME | base64Encode }}
+: Base64-encodes the variable's value. For example, `hello` becomes `aGVsbG8=`.
+
+{{ VARIABLE_NAME | base64Decode }}
+: Base64-decodes the variable's value. For example, `aGVsbG8=` becomes `hello`.
+
+Filters apply to both local and global variables. You can apply one filter per reference, and filter names are case-sensitive.