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+# CMAP Entry Creation Code Locations
+
+## Search Date
+2026-07-05
+
+## Summary
+This document identifies all locations in the pdftract codebase where CMAP (Character Map) entries are created for glyphs.
+
+## 1. ToUnicode CMap Entries (Character Code → Unicode Mappings)
+
+### Primary Entry Point
+**File:** `/home/coding/pdftract/crates/pdftract-core/src/font/cmap.rs`
+
+**Function:** `ToUnicodeMap::add_mapping()`  
+**Lines:** 86-88
+
+```rust
+/// Add a single mapping from source bytes to destination chars.
+///
+/// MARKER: CMAP entry creation point - this is where individual ToUnicode
+/// mappings are stored. Called by parse_beginbfchar() and parse_beginbfrange().
+/// See notes/bf-e4uvb-child-1.md for documentation.
+pub fn add_mapping(&mut self, src: Vec<u8>, dst: Vec<char>) {
+    self.mappings.insert(src, dst);
+}
+```
+
+### Call Sites
+
+#### a) Single-Character Mappings (beginbfchar)
+**Function:** `CMapParser::parse_beginbfchar()`  
+**Line:** 209  
+**Purpose:** Parses `beginbfchar...endbfchar` blocks for single character code → Unicode mappings
+
+#### b) Range Mappings - Contiguous Form
+**Function:** `CMapParser::parse_beginbfrange()`  
+**Line:** 292  
+**Purpose:** Expands contiguous ranges `<lo> <hi> <dst>` where each code in range maps to incrementing Unicode values
+
+#### c) Range Mappings - Explicit Array Form
+**Function:** `CMapParser::parse_beginbfrange()`  
+**Line:** 279  
+**Purpose:** Expands ranges with explicit arrays `<lo> <hi> [<d0> <d1> ...]` where each destination is specified individually
+
+### Parser Entry Point
+**Function:** `CMapParser::parse()`  
+**Lines:** 136-185  
+**Purpose:** Main parser that calls `parse_beginbfchar()` and `parse_beginbfrange()` when encountering those keywords
+
+---
+
+## 2. Codespace Range Entries (Byte-Width Boundaries)
+
+### Primary Entry Point
+**File:** `/home/coding/pdftract/crates/pdftract-core/src/cmap/codespace.rs`
+
+**Function:** `CodespaceParser::parse_codespace_block()`  
+**Lines:** 282-357
+
+**Creation Point:** Line 350
+```rust
+ranges.push(CodespaceRange::new(lo_arr, hi_arr, width as u8));
+```
+
+### Purpose
+Parses `begincodespacerange...endcodespacerange` blocks to define valid byte-width boundaries for multi-byte CJK encodings. Each `CodespaceRange` defines:
+- `lo`: Low bound (inclusive)
+- `hi`: High bound (inclusive)  
+- `width`: Byte width (1, 2, 3, or 4)
+
+### Constructor
+**Function:** `CodespaceRange::new()`  
+**Lines:** 56-60  
+**Purpose:** Creates a single codespace range with validation
+
+### Parser Entry Point
+**Function:** `CodespaceParser::parse()`  
+**Lines:** 233-279  
+**Purpose:** Main parser that calls `parse_codespace_block()` when encountering `begincodespacerange` keyword
+
+---
+
+## 3. Type1 Font Encoding Differences (Character Code → Glyph Name)
+
+### Primary Entry Point
+**File:** `/home/coding/pdftract/crates/pdftract-core/src/font/encoding.rs`
+
+**Function:** `DifferencesOverlay::parse()`  
+**Lines:** 163-209
+
+**Creation Point:** Lines 196-199
+```rust
+PdfObject::Name(name) => {
+    // Assign this name to the current cursor position
+    // MARKER: CMAP entry creation point - Type1 font encoding differences.
+    // See notes/bf-e4uvb-child-1.md for documentation.
+    if cursor <= 255 {
+        overlay.entries.push((cursor as u8, Arc::clone(name)));
+    }
+    cursor = cursor.saturating_add(1);
+}
+```
+
+### Purpose
+Parses `/Differences` arrays from Type1 font encodings to create sparse overlays that override base encodings. Format: `[n /Name1 /Name2 ... m /OtherName ...]` where integers reset the position and subsequent names are assigned to consecutive codes.
+
+### Data Structure
+**Type:** `DifferencesOverlay`  
+**Lines:** 129-232  
+**Purpose:** Stores sparse list of `(code, glyph_name)` overrides
+
+---
+
+## File Path Summary
+
+| Purpose | File Path | Function | Line Range |
+|---------|-----------|----------|------------|
+| ToUnicode add_mapping | `crates/pdftract-core/src/font/cmap.rs` | `ToUnicodeMap::add_mapping()` | 86-88 |
+| ToUnicode bfchar call | `crates/pdftract-core/src/font/cmap.rs` | `parse_beginbfchar()` | 209 |
+| ToUnicode bfrange explicit | `crates/pdftract-core/src/font/cmap.rs` | `parse_beginbfrange()` | 279 |
+| ToUnicode bfrange contiguous | `crates/pdftract-core/src/font/cmap.rs` | `parse_beginbfrange()` | 292 |
+| Codespace range creation | `crates/pdftract-core/src/cmap/codespace.rs` | `parse_codespace_block()` | 350 |
+| Type1 differences overlay | `crates/pdftract-core/src/font/encoding.rs` | `DifferencesOverlay::parse()` | 196-199 |
+
+---
+
+## Related Files (Reference)
+
+- **Codespace module:** `/home/coding/pdftract/crates/pdftract-core/src/cmap/mod.rs`
+- **Tokenizer:** `/home/coding/pdftract/crates/pdftract-core/src/cmap/tokenize.rs`
+- **Font resolver:** `/home/coding/pdftract/crates/pdftract-core/src/font/resolver.rs`
+- **Embedded fonts:** `/home/coding/pdftract/crates/pdftract-core/src/font/embedded.rs`
+- **Predefined CMap:** `/home/coding/pdftract/crates/pdftract-core/src/font/predefined_cmap.rs`
+
+---
+
+## Test Files
+
+- ToUnicode tests: `crates/pdftract-core/src/font/cmap.rs` (lines 507-732)
+- Codespace tests: `crates/pdftract-core/src/cmap/codespace.rs` (lines 634-898)
+- Encoding tests: `crates/pdftract-core/src/font/encoding.rs` (lines 371-669)
+
+---
+
+## Bead Reference
+This search was performed for bead **bf-4hwap** (explore task for CMAP entry creation).