Inserting special characters in Facebook is not always easy, but it is possible. As a rule, Facebook does not allow rich formatting in status updates and comments. However you can format text in blog entries with the Notes application. Use superscript and subscript to spell out mathematical expressions. Even if you do not need to use these in your Facebook posts, such specially formatted text can add novelty and interest to otherwise plain text postings.
Click "Notes" on the left navigation bar on either the Facebook home page or your profile page.
Click the "Write a Note" button on the upper right of the Notes page.
Enter a title for the note in the "Title" field.
Type in the main body whatever you want to post in the note. When you need to format text in subscript, enclose the text in the HTML subscript tags as follows:
Click the "Preview" button. You should see a message saying "This is a preview of your note" above the preview area.
Click "Edit" to resume editing the note or click "Publish" to publish it.
Click the Windows 7 button to open the Start menu. Type "Character Map" in the search box and click the Character Map program to launch it.
Check "Advanced view" to display more options. Select "Unicode" next to "Character set" and click "Unicode Subrange" below it. Click "Super/Subscript" in the "Group by" dialog box that appears on the right.
Click the font drop-down menu and select a font marked with a letter "O" next to its name. Press the "down" arrow key to browse through the fonts or click each one manually.
Click a subscript character in the main window. Click "Select," then click "Copy."
Log in to Facebook. Right-click the "Status" box, and click "Paste" to transfer the subscript character into your status update box. Click "Share" to publish.
Always append the closing tag to the text. If you forget to add it, all the text that follows will also appear as subscript. To format text in superscript, use the tags and instead. Usually, Windows fonts carry only superscript and subscript numbers and a few special characters, not letters.