  We give a modification of Mitchell's technique for adding objects of size
$\omega_2$ with conditions with finite working parts in which the collections
of models used as side conditions are very highly structured, arguably making
them more wieldy. We use one such forcing (essentially a `pure side conditions'
forcing) to answer affirmatively the question, asked independently by Shelah
and Velleman in the late 1980s, as to whether a $(\kappa^+,1)$-simplified
morass can be added by a forcing with working parts of size $<\kappa$.
