Typing codes for special character symbols

The symbols for special characters can be typed on a normal keyboard by holding down the Alt key and typing the 4 digit decimal character code on the numeric keypad (with Num Lock on).

These are not the same as the key codes generated by the keyboard when you type, but are the Unicode (formerly ASCII) representation of the characters.

Some useful character codes:

© - 0169 (also hex 00A9)
® - 0174 (00AE)

à - 0224 (00E0)
ç - 0231 (00E7)
è - 0232 (00E8)
é - 0233 (00E9)
ê - 0234 (00EA)
ë - 0235 (00EB)

÷ - 0247 (00F7)
x² (squared) - 0178 (00B2)
x³ (cubed) - 0179 (00B3)
µ (micro) - 0181 (00B5)
¼ - 0188 (00BB)
½ - 0189 (00BC)
¾ - 0190 (00BD)

For full information about characters and codes see the Unicode web site.
The codes in PDF form are in the code charts section. The ones I use most are Basic Latin and Latin-1.