On some ToL pages, the tree may have one or more labelled branches. The name printed on the branch is that of the group associated with the node (branching point) at the end (i.e., to the right) of the branch. In the following tree, Group B is the sister group of Group A, and it contains both Group C and Group D.
On the Tree of Life, branch labels are used to indicate group names that are noteworthy, eventhough that particular group does not have its own Tree of Life page.
If the phylogenetic relationships among the subgroups of a group are unknown, the Tree of Life page will show list of subgroups instead of a tree. On most ToL pages, this is just a plain list of group names, but some authors provide additional information in the form of an indented list. In the following list, the cascading indentations indicate the names of groups of decreasing inclusiveness: The group treated on this ToL page has three immediate subgroups: Group A, B and E. The subgroups of Group A will be treated on a separate ToL page, but the subgroups of the other two groups are listed on the current page: Group B has two subgroups, Group C and D. Group E has three subgroups, Group F, J, and M.
If there are any non-monophyletic groups or groups of uncertain phylogenetic position (incertae sedis) included in a classification, these groups are labelled with parenthetical remarks: