Model numbers are located on either the back or bottom of the seat, stamped on a white sticker. The manufacturing date will typically appear as a 4-digit date code representing the week and year of manufacture. The model number for wooden high chairs should be on a sticker under the seat. The date stamp is found underneath the T bars. It will look like a clock with an arrow pointing to the number for the month. The year will appear as a two-digit number on each side of the shaft of the arrow such as 06 or 99.