Provisions stipulated under the CCS (Leave) Rules, 1972 regulating Leave to certain specific category of central Govt. employees are explained here under.

1.         Leave to Probationers [CCS Leave Rule – 33(1)]
(a)        A probationer shall be entitled to leave under these rules if he had held his post substantively otherwise than on probation.
(b)        If, for any reason, it is proposed to terminate the services of a probationer, any leave which may be granted to him shall not extend –
(i)         Beyond the date on which the probationary period as already sanctioned or extended expires, or
(ii)        Beyond any earlier date on which his services are terminated by the orders of an authority competent to appoint him.

2.         Leave to a person on Probation [CCS Leave Rule – 33(2)]
A person appointed to a post on probation shall be entitled to leave under these rules as a temporary or a permanent Government servant according as his appointment is against a temporary or a permanent post.
Provided that where such person already holds a lien on a permanent post before such appointment, he shall be entitled to leave under these rules as a permanent Government servant.

3.         Leave to an Apprentice [CCS Leave Rule – 33(3)]
An apprentice shall be entitled to-
(a)        Leave, on medical certificate, on leave salary equivalent to half pay for a period not exceeding one month in any year of apprenticeship;
(b)        Extraordinary leave under Rule 32.

4.         Leave to Persons Re-employed after Retirement [CCS Leave Rule – 34]
In the case of a person re-employed after retirement, the provisions of these rules shall apply as if he had entered Government service for the first time on the date of his re-employment.

5.         Leave Preparatory to Retirement [CCS Leave Rule – 38]
(1)        A Government servant may be permitted by the authority competent to grant leave to take leave preparatory to retirement to the extent of earned leave due,not exceeding 300 days together with half pay leave due subject to the condition that such leave extends up to and includes the date of retirement (i.e. should not terminate before the date of retirement).
(2)(a)   Where a Government servant who is on foreign service in or under any Local Authority or a Corporation or Company wholly or substantially owned or controlled by the Government or a Body controlled or financed by the Government (hereinafter referred to as the local body) applies for leave preparatory to retirement, the decision to grant or refuse such leave shall be taken by the foreign employer with the concurrence of the lending authority under Central Government.
(b)        The Government servant on Foreign Service shall also be allowed to encash earned leave at his credit on the date of retirement in the manner provided in sub-rule (2) of Rule 39.
(3)        Where a Government servant is on Foreign Service in or under a local body other than the one mentioned in Clause (a) of sub-rule (2), leave preparatory to retirement shall be admissible to him only when he quits duty under the foreign employer.
Provided that where the Government servant continues in service under such foreign employer, the Government servant shall not be eligible for grant of cash payment in lieu of leave under Rule 39.
NOTE – The leave granted as leave preparatory to retirement shall not include extraordinary leave.