Strikethrough Tags
1. Log into Facebook. Click "Profile" in the upper-right corner. Navigate to the "Notes" or "Edit Profile" page. "Notes" is located on the left, just under your profile picture; "Edit Profile" is in the upper-right corner of the page.
2. Type <s>, then type in the text that you wish to appear with a line through it.
3. Type </s> at the end of the text you want struck out. You must do this or all the text after the <s> appears with a line through it.
4. Type <u> before the text you wish to appear with a line beneath it. Type the text. Finish by typing </u> or all the text after the <u> tag will have a line underneath it.
Using a Text Generator
1. Open your browser and log in to Facebook.
2. Open a free text converter such as Crazy DaVinci's Strikethrough Text Generator or Adam Varga's Unicode Strikethrough Text Tool in a separate tab or window.
3. Type the text that you want to convert. In the Crazy DaVinci converter, click the button for the kind of line you want: an underline, a diagonal slash through each letter or a line through the middle of all the letters. The Adam Varga converter is solely a strikethrough converter.
4. Copy the text using "Ctrl" + "C" on a PC keyboard or "Command" + "C if you're using a Mac.
5. Return to Facebook. Left-click inside the text field where you wish your text to appear. Paste the converted text using "Ctrl" + "V" on a PC keyboard or "Command" + "V" on a Mac.