tmux what does bind -t mean?

tmux what does bind -t mean?

I'm trying to configure my tmux so that I can copy & paste like in Vim.
Here is some code available in the tutorial:
unbind [
bind Escape copy-mode
unbind p
bind p paste-buffer
bind -t vi-copy 'v' begin-selection
bind -t vi-copy 'y' copy-selection
What does bind -t mean in the last two lines? It turns out that in the
copy mode, I can just type v to begin selection and y to yank, but I need
to type Prefixp to paste. Is it possible to bind p so that we can paste
without typing the Prefix like v and y?