Internal Revenue Service Form 1040 grows more complicated than ever. Wednesday, assuming you have filed your federal income tax on time, means you can forget about the U.S. tax code for another year.

BEHOLD IRS Form 1040, due Wednesday. Nearly a century after the creation of the federal income tax, Form 1040 is still one piece of paper. That ought to be a sign of simplicity, but is not.

Each year, Form 1040 becomes ever more bejeweled, much of it with generous intent.

Line 24, for example, offers a write-off of “certain expenses of reservists, performing artists and fee-basis government officials.” What a fee-basis official is, you have to discover for yourself.

Line 42 asks if you have “provided housing to a Midwestern displaced individual.” A Pacific Northwestern displaced individual does not count. But if you helped a Midwesterner, you can go to page 36 of the instructions and see if you win.

Form 1040 refers more than 30 times to the “instructions,” which in itself contains Tax Tables and forms to fill out called “worksheets.” The 1040 refers additionally to Form 4797, Form 2106 and about 30 other forms. It refers also to schedules A, B, C, D, E, F, H, SE and R.

Each schedule and form comes with instructions, some more difficult to fathom than the forms.

Here is a paragraph from the instructions for Form 1116, Foreign Tax Credit: “You pay or accrue tax to a foreign country or U.S. possession on income from foreign sources that is effectively connected with a trade or business in the United States. But if you must pay tax to a foreign country or U.S. possession on income from U.S. sources only because you are a citizen or a resident of that country or U.S. possession, do not use that tax in figuring the amount of your credit.”

An entire industry has arisen to find meaning in sentences like this. The tax industry employs thousands, though it is work untying the knots in which the people have trapped themselves. Others struggle with the tax code on their own, confident they can still wrestle it to the floor.

For them, April 15 should be a special day. It means they are done.