Tag: document in the code that 'tag' is compatible with ip only

src/detect-tag.c

@@ -71,6 +71,7 @@ void DetectTagRegister (void) {
     sigmatch_table[DETECT_TAG].Setup = DetectTagSetup;
     sigmatch_table[DETECT_TAG].Free  = DetectTagDataFree;
     sigmatch_table[DETECT_TAG].RegisterTests = DetectTagRegisterTests;
+    sigmatch_table[DETECT_TAG].flags |= SIGMATCH_IPONLY_COMPAT;
 
     const char *eb;
     int eo;

src/detect.c

@@ -1888,6 +1888,9 @@ int SignatureIsIPOnly(DetectEngineCtx *de_ctx, Signature *s) {
     if (s->sm_lists[DETECT_SM_LIST_AMATCH] != NULL)
         return 0;
 
+    /* TMATCH list can be ignored, it contains TAGs and
+     * tags are compatible to IP-only. */
+
     IPOnlyCIDRItem *cidr_item;
     cidr_item = s->CidrSrc;
     while (cidr_item != NULL) {