Help - Node/branch data ID
Node/branch data IDs are used give unique names to all node/branch data that are attached to a single node. Therefore it is not possible of e.g. having a text label and a hidden node data value with the same ID on the same node.
The IDs have to consist only of letters, digits and "_" (e.g. "id1", "123" or "_a" would be valid IDs, whereas "abc$" would not). They are used inside TreeGraph to identify one type of annotation and access it in various different features (like Copying node/branch data, Exporting node/branch data, Importing node/branch data, Adding support values, Set colors by node/branch data, Calculating node/branch data, assigning source data to pie chart labels and many more).
ID confilcts
If you e.g. insert a new label on a branch and specify an ID for it that is already used by another annotation on the same branch or the node a dialog will appear that asks you to solve this conflict. Here you can either choose Overwrite which will add the new label with the specified ID and remove the annotation currently identified by this ID from the same branch or node. Alternatively you can either change the ID of the new label or of the currently present annotation. That is done to ensure that all node/branch data IDs are unique on every branch.