What do -t and -s ':' mean in column -t -s ':' powers_list.txt?
-t
-s ':'
column -t -s ':' powers_list.txt
-t adds a title, and -s inserts a literal colon between output columns
-s
-t truncates long fields, and -s names an output file
-t converts every character to a tab, and -s sorts the rows
-t produces aligned table columns, and -s ':' splits input fields at colons