A predetermined synchronization pattern (40), a so-called VFO field, in, for example, the headers 3 of an information carrier, consists of sequences of 3T marks and spaces (41), of 8T marks and spaces (42) and of 5T marks and spaces (43). This sequence of patterns is advantageous for setting the dynamic range of an Automatic Gain Controlled (AGC) amplifier located within a device reading the information carrier.