Continuous ... It is independent from UML streaming, see clause 11.3.2.8. A streaming parameter may or may not apply to continuous flow, and a continuous flow may or may not apply to streaming parameters. Source OMG Systems Modeling Language (SysML) 1.6
Continuous rate is a special case of rate of flow (see Rate) where the increment of time between items approaches zero. It is intended to represent continuous flows that may correspond to water flowing through a pipe, a time continuous signal, or ... Source OMG Systems Modeling Language (SysML) 1.6
Restrictions on the rate at which entities flow along edges in an activity, or in and out of parameters of a behavior (see Rate in Figure 11-8). This includes both discrete and continuous flows, either of material, energy, or information. Source OMG Systems Modeling Language (SysML) 1.6