Reaction rules are defined in the reaction equation. By default, Reactor processes all reaction centers. When a reactivity rule is specified, Reactor returns only the product lists satisfying the rule. If a selectivity rule is specified, then Reactor sorts the product lists by the evaluation result of the rule (decreasing order) and returns product lists in this order. The selectivity tolerance determines the acceptance range of the selectivity rule, only the main product lists are accepted by default.

If the --no-rules, (-n), parameter is specified then some of the reaction rules are ignored depending on the parameter value:

r: the reactivity rule is ignored

s: the selectivity rule is ignored

t: the selectivity tolerance is ignored (all selectivity rule evaluation results are accepted)

rs: ignore both the reactivity rule and the selectivity rule

rt: ignore the reactivity rule and the selectivity tolerance (apply the selectivity rule only without tolerance, that is, all selectivity values are accepted and the selectivity rule is only used to sort the product lists)