"Text bold" icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ tango icon text Tango Format Text Bold
"Text strikethrough" icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ tango icon text Tango Format Text Strike Through
"Text itallic" icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ tango icon text Tango Format Text Itallic
"Text underlined" icon from Tango Project Since version 0.8.90 Tango Project icons are Public Domain: Tango Project FAQ tango icon text Tango Format Text Underline