This document discusses different types of forgery including:
1. Free hand forgery which involves copying a model signature without direct tracing.
2. Transplantation forgery which is transferring a signature or image from one document to another, often using computers or photocopying to commit fraud.
3. Forgery over a genuine signature which alters an original document signed legitimately to deceive the signer, such as changing amounts on a check.
Detection methods include examining paper fibers, ink, handwriting style, and instrument marks to determine if a signature or document has been tampered with or forged. Forensic analysis plays an important role in uncovering forgery attempts.