1. **Stricter Identifier Plausibility Check:** When a title doesn't explicitly start with "Chapter/Section/Part" + identifier (Pattern 1), but rather with a potential identifier followed by the rest of the title (Pattern 2, e.g., "9 Information Re-Founded"), the function now more carefully checks if that leading "word" (e.g., "9") is a plausible identifier.
- It specifically looks for:
- Purely numeric identifiers (e.g., "1", "09").
- Single alphabetic characters (e.g., "A", "b").
- Roman numerals (e.g., "I", "III", "iv").
- Short mixed alphanumeric identifiers (e.g., "1A", "A.1", "P2") up to a certain length, crucially ensuring these are not common English words of 3 or more letters. This prevents "The", "Why", "Information" from being treated as identifiers.
2. **Improved Prefix Determination:**
- If a plausible identifier is found (from Pattern 2), the prefix ("Chapter", "Section", "Part") is determined more accurately:
- Numeric or Roman numeral identifiers default to "Chapter".
- Single alphabetic identifiers default to "Section".
- Mixed identifiers (like "1A" or "A.1") will try to infer "Chapter" if starting with a digit, or "Section" if starting with a letter, otherwise defaulting to "Part".
- This is still overridden if the original title explicitly started with "chapter id", "section id", etc.
3. **Fallback Handling:** If no explicit "Chapter/Section/Part" structure is found and no plausible standalone identifier is detected at the beginning of the title, the function now correctly treats the input as a regular title and simply ensures its first letter is capitalized.
4. **Cleaner Output:** Ensures no trailing space after the colon if the title part is empty (e.g., "Chapter 1:").
These changes should correctly handle the examples you provided and lead to more accurate and "pretty" title formatting.