VTT markup operations are core features and used to mark the tag on a selected text. The procedures of VTT markup operations are described as follows:

• Add a new markup
  • Select: highlight a text
    • Highlight a selection of text by left Mouse: click + drag + release
    • Highlight a word by left mouse: double click
    • Highlight a line by left mouse: triple click
  • Action: tag the highlight text
    • Markup by popup menu (right mouse)
    • Markup by quick key (keys 1 - 9)
  • Notes on overlap operations:
    If the highlighted text include partial or full markups:
    • All overlapped markups are deleted and the highlight text is marked with the selected tag if the overlap is false (not checked)
    • Only the highlight text are marked with the selected tag if the overlap is true (checked). In this case, the visual effect might look odd since visual effects from tags are overlap and only the tag with latter position shown.
• View a markup
  • Select a markup
    • Select a markup by left mouse: single click
    • Use keys: <, >, [, ]
    • The selected markup has different (bigger font size) visual effect
  • Action: display information of the selected markup
    • By dialog box (key: m)
      This dialog box can be used to
      • Edit tag name, tag category, start position, end position, and annotation of a selected markup
      • Delete markup from markups list
• Change a markup
  • Select a markup
    • Select a markup by left mouse: single click
    • Use keys: <, >, [, ]
    • The selected markup has different (bigger font size) visual effect
  • Action: tag the selected markup
    • By popup menu (right mouse)
    • By quick keys (keys: 1 - 9)
    • By dialog box (key: m)
• Delete a markup
  • Select a markup
    • Select a markup by left mouse: single click
    • Use key: <, >, [, ]
    • The selected markup has different (bigger font size) visual effect
  • Action: delete the selected markup
    • By popup menu (right mouse)
    • By menu bar (Markups -> Delete)
    • By quick key (key: 0)
    • By dialog box (key: m)
• Join a selected markup and the next markup
  • Select a markup
    • Select a markup by left mouse: single click
    • Use key strokes: <, >, [, ]
    • The selected markup has different (bigger font size) visual effect
  • Action: join the selected markup and the next markup
    • By quick key (key: j)

In addition, VTT provides following features to ease markup processes:

• Undo
  • Undo the last markup operation (add, change, delete, join)
  • beep when it is not applicable
  • Action:
    • By popup menu (right mouse)
    • By menu bar (Markups -> Undo)
    • By quick key (key: u)
• Redo
  • Redo the last markup operation (add, change, delete, join)
  • beep when it is not applicable
  • Action:
    • By popup menu (right mouse)
    • By menu bar (Markups -> Redo)
    • By quick key (key: r)

• Delete All
  • delete all markups and set the text as plain text
  • Action:
    • By popup menu (right mouse)
    • By menu bar (Markups -> Delete All)