Alt Codes:
Alt + 3 = ♥, but you need to know more. To use the Alt codes you must have the Number Keypad on. On a PC, just press the NumLock key and light should come on and you can use the Alt codes. For laptops, You have to use the Fn + Alt keys together and the number keypad is the numbers on certain dedicated letters keys. Check your Help for your laptop to show which key engages and locks the Fn (Number Pad) on or see: How to Use the Numeric Keypad on Your Laptop - http://www.dummies.com/how-to/content/how-to-use-the-numeric-keypad-on-your-laptop.navId-323008.html
How to Type Symbols Using the ALT Key: http://www.wikihow.com/Type-Symbols-Using-the-ALT-Key
This only works with programs which accept an ASCII input, such as email, Notepad, WordPad, etc. Try it for the program you are using. Programs that do not support this feature may render the character as a question mark (?). Character encodings and character sets do vary by computer system, so you may find that one code does different things on a Windows machine versus a Macintosh. This only works with the number pad on Desktops. These codes may not work with laptops, notebooks, or hand held computer devices etc., depending on your machine: most laptops have a blue extra key 'Fn', and little blue numbers on the keys 789uiojklm,. - if you have these, you can use ALT + Fn, and then the little blue numbers on these keys to get the same effect. ( http://www.wikihow.com/Type-Symbols-Using-the-ALT-Key )
Some symbols may not show because your computer does not contain the font set and/or your browser is not set to the correct Character Encoding (utf-8 is good). Changing browser's encoding is usually done from its View Menu. Unicode browser display test: http://home.tiscali.nl/t876506/entitiesTips.html
Alt Codes Only:
http://www.questgems.com/alt_codes.htm
http://knopok.net/symbol-codes/alt-codes
http://usefulshortcuts.com/alt-codes
http://www.planetburrito.com/tb/alt_codes.html
http://thurmania.com/Altchart.html
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