An example according to the present specification relates to a technique relating to a configuration of a preamble in a wireless LAN (WLAN) system. A transmitting STA may generate and transmit an EHT PPDU. The EHT PPDU may include an L-SIG field, an RL-SIG field, and a control field. A result of “modulo 3 operation” to a length field value of the L-SIG field may be set to “0”. The RL-SIG field may be configured the same as the L-SIG field. The control field may include 3-bit information relating to a version of a PPDU.