Add support for the alternative base64 encoding in RFC 4648 section 5 to `WhenBase64Unescaped`.
PiperOrigin-RevId: 507527786
Change-Id: Ie5e088b1814981f6c760d7e25418a430172705ec
diff --git a/docs/reference/matchers.md b/docs/reference/matchers.md
index be96281..243e3f9 100644
--- a/docs/reference/matchers.md
+++ b/docs/reference/matchers.md
@@ -102,7 +102,7 @@
| `StrCaseNe(string)` | `argument` is not equal to `string`, ignoring case. |
| `StrEq(string)` | `argument` is equal to `string`. |
| `StrNe(string)` | `argument` is not equal to `string`. |
-| `WhenBase64Unescaped(m)` | `argument` is a base-64 escaped string whose unescaped string matches `m`. |
+| `WhenBase64Unescaped(m)` | `argument` is a base-64 escaped string whose unescaped string matches `m`. The web-safe format from [RFC 4648](https://www.rfc-editor.org/rfc/rfc4648#section-5) is supported. |
`ContainsRegex()` and `MatchesRegex()` take ownership of the `RE` object. They
use the regular expression syntax defined
