There is an interesting aspect of predicted reaction libraries. The HL7 RIM on which SPL is based has a concept of (re-)act(ion) "mood", which is a code that indicates whether an act is actually occurring or planned or defined as a possible action. Among the SAVI reactions, only a very small number of them have so far been successfully carried out. While the "mood" could be used to indicate the hypothetical vs. actual feasibility status of the SAVI reaction, it is probably best to associate this attribute with a characteristic to the reaction. Characteristics are general parameter namevalue pairs which can be defined to indicate different properties of the reaction, such as reversibility, enthalpy, etc. but also whether the reaction is predicted vs. has been observed (about actual reaction processes see further below.) In the current version of R-SPL, the mood code is not there to change in the actual SPL schema. We plan to add this in future releases.