description: 
                                       
                                       A code specifying the meaning and purpose of every ActRelationship instance. Each
                                          of its values implies specific constraints to what kinds of Act objects can be related
                                          and in which way.
                                       
                                       
                                       
                                          Discussion: The types of act relationships fall under one of 5 categories:
                                       
                                       
                                       1.) (De)-composition, with composite (source) and component (target)
                                       
                                       2.) Sequel which includes follow-up, fulfillment, instantiation, replacement, transformation,
                                          etc. that all have in common that source and target are Acts of essentially the same
                                          kind but with variances in mood and other attributes, and where the target exists
                                          before the source and the source refers to the target that it links back to.
                                       
                                       
                                       3.) Pre-condition, trigger, reason, contraindication, with the conditioned Act at
                                          the source and the condition or reason at the target.
                                       
                                       
                                       4.) Post-condition, outcome, goal and risk, with the Act at the source having the
                                          outcome or goal at the target.
                                       
                                       
                                       5.) A host of functional relationships including support, cause, derivation, etc.
                                          generalized under the notion of "pertinence".