Joint Stock Companies or simply companies come into existence after getting registered under Companies Act. Companies have to abide by the clauses contained in the Companies Act. For example Companies Act, 2013 provides format of Profit & Loss A/c and Balance Sheet. Notes to those formats also provide details about how various items are to dealt with and depicted.
The Companies Act contains so many provisions relating to Accounting. For example provisions related to Share Capital, Security Premium, Calls, Interest on Calls in Arrears, Interest on Calls in Advance, Forfeiture of Shares, Reissue of Forfeited Shares, Issue and Redemption of Preference Shares, Issue of Bonus Shares, Transfer to General Reserve, Depreciation, Remuneration of Management, Issue and Redemption of Debentures, Treatment of Incorporation Expenses, etc. etc.
Unless you have knowledge related to above provisions, you cannot do proper accounting for companies. This is the reason why it is necessary to study Corporate Accounting or Company Accounts.