Ok here is the extract from it where it tries to explain gross receipts for professionals
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5.19 In the case of a professional, the expression "gross receipts" in profession would include all receipts arising from carrying on of the profession. A question may, however, arise as to whether the out of pocket expenses received by him should form part of his gross receipts for purposes of this section. Normally, in the case of solicitors, advocates or chartered accountants, such out of pocket expenses received in advance are credited in a separate client's account and utilised for making payments for stamp duties, registration fees, counsel's fees, travelling expenses etc. on behalf of the clients. These amounts, if collected separately either in advance or otherwise, should not form part of the "gross receipts". If, however, such out of pocket expenses are not specifically collected but are included/collected by way of a consolidated fee, the whole of the amount so collected shall form part of gross receipts and no adjustment should be made in respect of actual expenses paid by the professional person for and/or on behalf of his clients out of the gross fees so collected. However, the amount received by way of ...advance for which services are yet to be rendered will not form part of the receipts, as such advances are the liabilities of the assessee and cannot be treated as his receipts till the services are rendered.
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Here again "gross receipts" are described as "receipt". The "receivable" clauses in ICDS would kick in only if the mercantile system is adopted, is what I understand.
Further...this guideline at various places (as given by me in previous replies) say that according to section 145 (1) one who derive income under the head "profits and gains of buissiness or profession" can use either the cash or mercantile system of accounting