In the Custom Bridges section of the Development Guide, after the "Example: Custom StringBridge implementation", there is this sentence :

Given the string bridge defined in ?, any property or field can use this bridge thanks to the @FieldBridge annotation:

If you look at the 6.4 version of the Development Guide, it shows a link in the position where the "?" is located:

Given the string bridge defined in Example 14.25, "Custom StringBridge implementation", any property or field can use this bridge thanks to the @FieldBridge annotation: