this is the first time i heard of a relieving letter, changed jobs so many times liao. neither i had any interviewers asking me of any relieving letters.

there is no need to prove the work you did or the responsibilities you have. whatever you wrote in your resume, the interviewers will assume them to be true. if not, they will ask you questions lor. in any case, got probation period ma, you are not what you said you are, you're out.

for salary, usually they will ask your for ur pay slip. by law, need to have. if dont have, show cpf statement.

in conclusion, there's no need for a relieving letter at all. you dont show it to your next employer. can use as recycle paper right away