The link which you referred me to says this -
4. Letter from Manager - If HR refuses to give you a letter, then ask your manager to issue you a letter on white paper (it should cover all the requisite points), along with a copy of his visiting card and company ID card and get the letter notarized. Submit it along with a Letter of Explanation (LOE).
In India notary is done on non-judicial stamp paper only a notary lawyer only could sign and attest it on a stamp paper.