Index: gc_core/js/lang_core/gc_engine.js
==================================================================
--- gc_core/js/lang_core/gc_engine.js
+++ gc_core/js/lang_core/gc_engine.js
@@ -231,10 +231,13 @@
             this.sText = this.sText.replace(/'/g, "’");
         }
         if (this.sText.includes("‑")) {
             this.sText = this.sText.replace(/‑/g, "-"); // nobreakdash
         }
+        if (this.sText.includes("@@")) {
+            this.sText = this.sText.replace(/@@+/g, "");
+        }
 
         // parse sentence
         for (let [iStart, iEnd] of gc_engine.getSentenceBoundaries(this.sText)) {
             try {
                 this.sSentence = this.sText.slice(iStart, iEnd);
@@ -795,12 +798,12 @@
         let ln = m.end[iGroup] - m.start[iGroup];
         let sNew = "";
         if (sRepl === "*") {
             sNew = " ".repeat(ln);
         }
-        else if (sRepl === ">" || sRepl === "_" || sRepl === "~") {
-            sNew = sRepl + " ".repeat(ln-1);
+        else if (sRepl === "_") {
+            sNew = "_".repeat(ln);
         }
         else if (sRepl === "@") {
             sNew = "@".repeat(ln);
         }
         else if (sRepl.slice(0,1) === "=") {

Index: gc_core/py/lang_core/gc_engine.py
==================================================================
--- gc_core/py/lang_core/gc_engine.py
+++ gc_core/py/lang_core/gc_engine.py
@@ -260,10 +260,12 @@
             sText = sText.replace(" ", ' ') # nnbsp
         if "'" in sText:
             sText = sText.replace("'", "’")
         if "‑" in sText:
             sText = sText.replace("‑", "-") # nobreakdash
+        if "@@" in sText:
+            sText = re.sub("@@+", "", sText)
 
         # parse sentences
         for iStart, iEnd in _getSentenceBoundaries(sText):
             if 4 < (iEnd - iStart) < 2000:
                 try:
@@ -687,11 +689,13 @@
         "text processor: write <sRepl> in <sText> at <iGroup> position"
         nLen = m.end(iGroup) - m.start(iGroup)
         if sRepl == "*":
             sNew = " " * nLen
         elif sRepl == "_":
-            sNew = sRepl + " " * (nLen-1)
+            sNew = "_" * nLen
+        elif sRepl == "@":
+            sNew = "@" * nLen
         elif sRepl[0:1] == "=":
             sNew = globals()[sRepl[1:]](sText, m)
             sNew = sNew + " " * (nLen-len(sNew))
             if bUppercase and m.group(iGroup)[0:1].isupper():
                 sNew = sNew.capitalize()