diff -r c06d08c8a1b8 -r 66c1d31e2f97 common/corpus-common-addon/addon/utils/utils.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/common/corpus-common-addon/addon/utils/utils.js	Tue Mar 01 23:35:33 2016 +0100
@@ -0,0 +1,5 @@
+import * as constants from 'corpus-common-addon/utils/constants';
+
+export function isBnfLink(s) {
+  return s.startsWith(constants.BNF_BASE_URL) || s.startsWith(constants.BNF_ARK_BASE_URL) || s.startsWith(constants.BNF_ARK_BASE_ID);
+};