ASC 230 defines financing activities broadly, and a number of specific items have been placed there by standard setters. ASU 2016-09 put cash paid to tax authorities for withheld shares in financing, and ASU 2016-15 did the same for debt prepayment and extinguishment costs and for contingent consideration paid well after an acquisition, up to the amount recognized at the acquisition date. Under ASC 842, principal payments on finance leases are financing, while operating lease payments are operating. In XBRL, the residual line is tagged ProceedsFromPaymentsForOtherFinancingActivities, and a positive value means a net inflow. Items that are often broken out have their own elements, including PaymentsRelatedToTaxWithholdingForShareBasedCompensation and FinanceLeasePrincipalPayments.
What ends up in "other" depends on how much detail the company provides. Some filers show every item above on its own line and leave little in the residual; others group several material items together. For companies with large equity compensation programs, withholding tax payments alone can be significant, and they function much like share repurchases because the company pays cash instead of issuing the withheld shares.
Analysts should look inside this line before calculating shareholder returns or net borrowing. Finance lease principal is economically a debt repayment, and withholding tax payments are economically part of the cost of equity compensation. Leaving them in "other" can understate both a company's debt service and its true return of capital to shareholders.