About Polish letters
Polish adds nine letters: ą, ć, ę, ł, ń, ó, ś, ź and ż. Most Polish speakers use the Polish (Programmers) layout, where Alt Gr plus the base letter types the accented version.
On a Mac the Polish Pro layout works the same way with Option plus the base letter.
The ł has a stroke, not an accent, so it cannot be typed with a dead key on a standard layout.
Polish letters: names and codes
Every special letter in Polish, with the Windows Alt code where one exists, the hex code to type in Word followed by Alt+X, the Mac shortcut and the HTML entity. Click a letter to copy it.