diff --git a/docs/internals.adoc b/docs/internals.adoc
index cfe175f81..b2a1a0723 100644
--- a/docs/internals.adoc
+++ b/docs/internals.adoc
@@ -786,10 +786,10 @@ better viewers let us know; ZGRViewer isn't great for large graphs.
 Tree files are dumps of the AST Tree and are produced between every major
 algorithmic stage.  An example:
 
-     NETLIST 0x90fb00 <e1> {a0}
-    1: MODULE 0x912b20 <e8822> {a8}  top  L2 [P]
-   *1:2: VAR 0x91a780 <e74#> {a22} @dt=0xa2e640(w32)  out_wide [O] WIRE
-    1:2:1: BASICDTYPE 0xa2e640 <e2149> {e24} @dt=this(sw32)  integer kwd=integer range=[31:0]
+     NETLIST 0x90fb00 <e1> {a0ah}
+    1: MODULE 0x912b20 <e8822> {a8ah}  top  L2 [P]
+   *1:2: VAR 0x91a780 <e74#> {a22ah} @dt=0xa2e640(w32)  out_wide [O] WIRE
+    1:2:1: BASICDTYPE 0xa2e640 <e2149> {e24ah} @dt=this(sw32)  integer kwd=integer range=[31:0]
 
 The following summarizes the above example dump, with more detail on each
 field in the section below.
@@ -807,8 +807,9 @@ the `MODULE`, which in turn is the `op1p` pointer under the `NETLIST`
 | `<e74>` | means the 74th edit to the netlist was the last modification to
 this node.
 
-| `{a22}` | indicates this node is related to line 22 in the source filename
-"a", where "a" is the first file read, "z" the 26th, and "aa" the 27th.
+| `{a22ah}` | indicates this node is related to the source filename "a",
+where "a" is the first file read, "z" the 26th, and "aa" the 27th.  Then
+line 22 in that file, then column 8 (aa=0, az=25, ba=26, ...).
 
 | `@dt=0x...` | indicates the address of the data type this node contains.
 
diff --git a/src/V3AstNodes.cpp b/src/V3AstNodes.cpp
index e84452d7b..e3a2bba02 100644
--- a/src/V3AstNodes.cpp
+++ b/src/V3AstNodes.cpp
@@ -970,7 +970,8 @@ void AstNode::dump(std::ostream& str) const {
         << cvtToHex(this)
         //<<" "<<cvtToHex(this)->m_backp
         << " <e" << std::dec << editCount() << ((editCount() >= editCountLast()) ? "#>" : ">")
-        << " {" << fileline()->filenameLetters() << std::dec << fileline()->lastLineno() << "}";
+        << " {" << fileline()->filenameLetters() << std::dec << fileline()->lastLineno()
+        << fileline()->firstColumnLetters() << "}";
     if (user1p()) str << " u1=" << cvtToHex(user1p());
     if (user2p()) str << " u2=" << cvtToHex(user2p());
     if (user3p()) str << " u3=" << cvtToHex(user3p());
diff --git a/src/V3FileLine.cpp b/src/V3FileLine.cpp
index 915de3bbf..2123a5f1b 100644
--- a/src/V3FileLine.cpp
+++ b/src/V3FileLine.cpp
@@ -276,6 +276,12 @@ const string FileLine::filebasenameNoExt() const {
     return name;
 }
 
+const string FileLine::firstColumnLetters() const {
+    char a = ((firstColumn() / 26) % 26) + 'a';
+    char b = (firstColumn() % 26) + 'a';
+    return string(1, a) + string(1, b);
+}
+
 const string FileLine::profileFuncname() const {
     // Return string that is OK as a function name - for profiling
     string name = filebasenameNoExt();
diff --git a/src/V3FileLine.h b/src/V3FileLine.h
index 28da1d275..6603ae0df 100644
--- a/src/V3FileLine.h
+++ b/src/V3FileLine.h
@@ -200,6 +200,7 @@ public:
     const string filenameLetters() const { return singleton().filenameLetters(m_filenameno); }
     const string filebasename() const;
     const string filebasenameNoExt() const;
+    const string firstColumnLetters() const;
     const string profileFuncname() const;
     const string xml() const {
         return "fl=\"" + filenameLetters() + cvtToStr(lastLineno()) + "\"";