One-Health Consensus Reference Annotation Checklist (OH-CRAC) CRAC 3.1. Practical aspects on sample selection This section describes how the specific sampling units were chosen based on the sampling plan that is described in section 2.4 (Sampling plan). In contrast to the information given in 2.4, this section should describe how the real "implementation" of the sampling plan took place, as sometimes the "field work" is done by other actors than the planning.