How to express that a tree was generated by simulating under a specified process?

[cboettig]

Simulated trees or sets of trees are commonly used in testing estimation routines of branching process models. Simulation of a phylogeny conditioned on number of tips involves some subtlety (Stadler 2011 ); an R package is dedicated to this task alone (TreeSim).

How do we express that a tree has been generated in this way, rather than inferred from a character matrix? Is it necessary to distinguish more broadly between simulated data and "real" data?