[dragonwriter]

Gross salary usually refers to #2 in the US, to, and, contrary to the upthread suggestion, just as in Europe, there is an “employer portion” (which in the US includes some of retirement and retirement healthcare, but not current healthcare—that is, specifically, federally half of the tax for Social Security and Medicare,—plus, a portion of the cost of federal and state unemployment insurance) which is not included in gross salary because it is paid out of employer taxes rather than employee taxes. There are also sometimes employer-provided benefits that while part of total compensation are not part of gross salary , and may or may not be part of taxable income; some portion of employer-provided healthcare cost is frequently part of this, and, though this is almost entirely a public-sector concern now, some portion of employer pension costs also frequently would be part of this, where a pension exists at all (adding these employer taxes and benefits to gross salary isn't the total cost to the employer of the employee either, as there is overhead and other employer costs for employment that that still excludes.)

It is true that the spread between #2 and #3 (when limited only to the required taxes and any benefits not part of salary, which seems to be the intention) is typically greater in Europe than the US, as the supported social services are greater.