FSH supports an easy syntax for specifying a Quantity when the units are taken from UCUM:

* valueQuantity = 155.0 '[lb_av]'

But there is no way to specify the `unit` field when doing this. It might make sense to support a syntax like:

* valueQuantity = 155.0 '[lb_av]' "lb"

where the valueQuantity.unit would then get set to "lb". The unit is meant to be a human readable value, and there is plenty of precedent for setting human readable values as strings at the end of assignments, so I don't think users would find this a confusing addition.