Link to varnish-cache documentation for regsub(all)?

src/vmod_re.vcc

@@ -33,13 +33,17 @@ SYNOPSIS
 DESCRIPTION
 ===========
 
+.. _regsub(): https://varnish-cache.org/docs/trunk/reference/vcl.html#regsub-str-regex-sub
+
+.. _regsuball(): https://varnish-cache.org/docs/trunk/reference/vcl.html#regsuball-str-regex-sub
+
 Varnish Module (VMOD) for matching strings against regular expressions,
 and for extracting captured substrings after matches.
 
 Regular expression matching as implemented by the VMOD is equivalent
 to VCL's infix operator ``~``. The VMOD is motivated by the fact that
 backreference capture in standard VCL requires verbose and suboptimal
-use of the ``regsub`` or ``regsuball`` functions. For example, this
+use of the `regsub()`_ or `regsuball()`_ functions. For example, this
 common idiom in VCL captures a string of digits following the
 substring ``"bar"`` from one request header into another::
 
@@ -219,7 +223,7 @@ Description
 	scope (client or backend context), or a fallback string in
 	case the extraction fails.  Backref 0 indicates the entire
 	matched string. Thus this function behaves like the ``\n``
-	symbols in ``regsub`` and ``regsuball``, and the ``$1``,
+	symbols in `regsub()`_ and `regsuball()`_, and the ``$1``,
 	``$2`` ...  variables in Perl.
 
 	After unsuccessful matches, the ``fallback`` string is returned
@@ -227,7 +231,7 @@ Description
 	is ``"**BACKREF METHOD FAILED**"``.
 
 	The VCL infix operators ``~`` and ``!~`` do not affect this
-	method, nor do the functions ``regsub`` or ``regsuball``.
+	method, nor do the functions `regsub()`_ or `regsuball()`_.
 
 	If ``backref`` is called without any prior call to ``match``
 	for this object in the same task scope, then an error message