Dear Mr. Arbind, the special allowance in your case should be construed as DA, as 17% of the salary package mentioned by you should be to cover the cost of living, even though there was no mechanism to arrive at this figure as in the case of unionized employees who are enjoying the dearness allowance based on the mechanism of local cost of living/All India consumer price, as the case may be.
The allocation of a major portion of the gross salary in the name of Special Allowance may be to circumvent the definition of salary under the Payment of Gratuity Act 1972, inasmuch as to lessen the employer's financial commitment to gratuity to employees, especially senior executives in management cadre. It is understandable and logically tenable to allocate a reasonable portion (%) of the gross salary into HRA (up to 50%), Conveyance Allowance, City Compensatory Allowance, Dress/Washing Allowance, etc. Bereft of all these allowances, a single component styled as Special Allowance with a considerable percentage of the gross salary is a point of dispute.
The issue regarding Special Allowance as part of salary in addition to Basic Salary has to be taken up with the controlling Authority under the Payment of Gratuity Act 1972 for a final decision. If the Controlling Authority negates your representation, then the issue should be taken to the Appellate Authority. There is strength in your case. The employer cannot interpret the definition of salary solely based on the wording of the Payment of Gratuity Act 1972. In fact, it should be interpreted in the spirit and logical conclusion, and I am sure the Courts can view this social security legislation in a more pragmatic, logical, and analytical manner, giving you bright chances of success. I am not in a position to refer to any judicial pronouncements/case law in this regard.
Let other experts shed light on this matter.