Описание тега affix
An additional element placed at the beginning or end of something.
An additional element placed at the beginning or end of a root, stem, or word, or in the body of a word, to modify its meaning. In Twitter Bootstrap it is prepend.
Prepended and appended inputs in BootStrap.
Add text or buttons before or after any text-based input. Do note that select elements are not supported here.
Wrapping an .add-on and an input with one of two classes to prepend or append text to an input.