A timestamped comment or remark intended for human consumption. There should be no assumption that semantics can be extracted from this field by a computer. Neither should there be an assmumption that any two humans will interpret the information in the same way (i.e., it may not be interoperable). The date and time when the comment was logged. A floating point value between zero (inclusive) and one (inclusive) This value can be zero but cannot be negative. This value can not be greater than one.