The ornamental design for an electronictag, as shown.
FIG. 1 is a perspective front view of an electronic tag according to my new design, shown in use on a suitcase depicted in broken lines;
FIG. 2 is a perspective front view of the electronic tag;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a side view thereof; and,
FIG. 6 is an end view thereof.
The broken lines in FIG. 1 illustrate environment and form no part of the claimed design. The broken lines in FIGS. 2-6 illustrate portions of the article and form no part of the claimed design.