If you create an entry which is identical to an existing entry, the two are hyperlinked together. They share the same descendants.
If you do not wish this to happen, simply click on the namesake icon to the left of the new entry.
Why should Namesakes be useful?
Namesakes can be prevented either before or after they happen by selecting the Namesake on/off option. This marks the chosen entry(ies) with a cross, signifying that the entry(ies) cannot be Namesaked. This is useful if you know you are going to reuse a term and do not wish future occurrences to be connected to it. If a Namesake with descendants is non-Namesaked, then the descendants disappear from that entry but remain attached to its erstwhile Namesakes.
Use the same command to re-enable Namesaking.
The currently active entry in the selected block (the one with a triangle on its icon) is used as the basis for the setting. e.g. if the active entry is a namesake, then it, and all the others in the block will be turned into non-namesakes. And vice versa.
If a Namesake is re-enabled after it has acquired its own descendants, you are invited to merge the two sets. BrainStorm does this intelligently, avoiding the repetition of Namesakes among the descendants, but allowing new descendants to be added.
Use: