iText 2.1.6 Released on June 16, 2009, and announced the support timestamps and ocsp (timestamp support inspired by contributions by Aiken Sam and Martin Brunecky). also introduced many other changes,
- PdfPKCS7: Added the RIPEMD algorithm.
- AcroFields: Some tools produce invisible signatures without an entry in the page annotation array.
- SpecialSymbol: If PHI is ‘F’ the phi should be ‘f’.
- Removed some unnecessary e.printStackTrace occurences.
and so on, for details, please visit here.