Columbus, J. Travis and Smith, James P. Jr. (2010) "Nomenclatural Changes for Some Grasses in California and the Muhlenbergia Clade (Poaceae)," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 28: Iss. 1, Article 7. (Link)
Unintended disagreements occur when a parent (B) is
thinned by swapping a child (E) to another part of the
taxonomic tree, resulting in existing IDs of the parent being interpreted
as disagreements with existing IDs of the swapped child.
Identification
ID 2 of taxon E will be an unintended disagreement with ID 1 of taxon B after the taxon swap
If thinning a parent results in more than 10 unintended disagreements, you
should split the parent after swapping the child to replace existing IDs
of the parent (B) with IDs that don't disagree.