expand declareMetric text

(cherry picked from commit 0ffd83db942bab775a1363a373d5cb01b8455a86)

diff --git a/pdns/dnsdistdist/docs/reference/custommetrics.rst b/pdns/dnsdistdist/docs/reference/custommetrics.rst
index b260613449fc06190458e779d32ef9c9b800d27e..b2f5b517be3d2e2b787e60e371609fbb87fbfd63 100644 (file)
--- a/pdns/dnsdistdist/docs/reference/custommetrics.rst
+++ b/pdns/dnsdistdist/docs/reference/custommetrics.rst
@@ -17,6 +17,9 @@ Then you can update those at runtime using the following functions, depending on
   .. versionchanged:: 1.8.1
     This function can now be used at runtime, instead of only at configuration time.
 
+  Re-declaring an existing metric with the same name and type will not reset it.
+  Re-declaring with the same name but a different type will cause one of them to be masked.
+
   Returns true if declaration was successful.
 
   :param str name: The name of the metric, lowercase alphanumerical characters and dashes (-) only