A data management unit of a glucose meter comprising • a data storage adapted to store o a plurality of measurement values of a physiological parameter, namely a blood glucose level, o for each measurement value an associated event tag, o for each measurement value an associated time stamp, o an associated time range for tagging preselection for each of at least two meal events, • a processor adapted to o receive a new measurement value from a measurement unit, o assign an associated time stamp to the new measurement value, if an associated time stamp does not yet exist with the new measurement value, o receive selection data containing the information that the user has, in a first input, manually selected and/or confirmed one of o a "before meal" tag component and o an "after meal" tag component with regard to each new measurement value, o automatically select, based on the selection data and on a comparison of the time stamp of the new measurement value with the associated time ranges for tagging preselection of the at least two meal events, an additional associated tag referring to the one of the at least two meal events, wherein o the chosen one of the "before meal" tag component and the "after meal" tag component constitutes only a first component of an event tag for the new measurement value, and o the automatically selected additional associated tag constitutes a second component of the event tag for the new measurement value, such that the event tag selected for the new measurement value is a composite tag, wherein the selection data is used to distinguish between and to determine one of two associated meal events identified by the comparison with overlapping time ranges for tagging preselection. • a data storage adapted to store o a plurality of measurement values of a physiological parameter, namely a blood glucose level, o for each measurement value an associated event tag, o for each measurement value an associated time stamp, o an associated time range for tagging preselection for each of at least two meal events, o a plurality of measurement values of a physiological parameter, namely a blood glucose level, o for each measurement value an associated event tag, o for each measurement value an associated time stamp, o an associated time range for tagging preselection for each of at least two meal events, • a processor adapted to o receive a new measurement value from a measurement unit, o assign an associated time stamp to the new measurement value, if an associated time stamp does not yet exist with the new measurement value, o receive selection data containing the information that the user has, in a first input, manually selected and/or confirmed one of o a "before meal" tag component and o an "after meal" tag component with regard to each new measurement value, o automatically select, based on the selection data and on a comparison of the time stamp of the new measurement value with the associated time ranges for tagging preselection of the at least two meal events, an additional associated tag referring to the one of the at least two meal events, wherein o the chosen one of the "before meal" tag component and the "after meal" tag component constitutes only a first component of an event tag for the new measurement value, and o the automatically selected additional associated tag constitutes a second component of the event tag for the new measurement value, o receive a new measurement value from a measurement unit, o assign an associated time stamp to the new measurement value, if an associated time stamp does not yet exist with the new measurement value, o receive selection data containing the information that the user has, in a first input, manually selected and/or confirmed one of o a "before meal" tag component and o an "after meal" tag component with regard to each new measurement value, o a "before meal" tag component and o an "after meal" tag component o automatically select, based on the selection data and on a comparison of the time stamp of the new measurement value with the associated time ranges for tagging preselection of the at least two meal events, an additional associated tag referring to the one of the at least two meal events, wherein o the chosen one of the "before meal" tag component and the "after meal" tag component constitutes only a first component of an event tag for the new measurement value, and o the automatically selected additional associated tag constitutes a second component of the event tag for the new measurement value, o the chosen one of the "before meal" tag component and the "after meal" tag component constitutes only a first component of an event tag for the new measurement value, and o the automatically selected additional associated tag constitutes a second component of the event tag for the new measurement value, such that the event tag selected for the new measurement value is a composite tag, wherein the selection data is used to distinguish between and to determine one of two associated meal events identified by the comparison with overlapping time ranges for tagging preselection.