Early signs of the Xiaomi 12S and Xiaomi 12S Pro emerge online
The first indications of the Xiaomi 12S series have emerged online, merely a few months after Xiaomi revealed the 12, 12X and the 12 Pro. However, Xiaomi has only been selling the trio for approximately a month outside China, so it is doubtful that the company will announce the 12S or 12S Pro any time soon. Incidentally, Xiaomi is expected to release the 12 Lite and 12 Ultra soon, though.
Regardless, Xiaomiui has noticed the Xiaomi 12S and Xiaomi 12S Pro on IMEI databases. As the screenshots below show, the IMEI listings refer to the pair as 2206123SC and 2206122SC, respectively, denoting that these are Chinese variants. Apparently, the 'L3S' and 'L2S' also have the codenames 'diting' and 'unicorn', although Xiaomiui has provided no evidence for these claims. Additionally, Xiaomiui previously claimed that 'unicorn' was the codename for the Xiaomi 12 Ultra, not the Xiaomi 12S Pro.
Separately, @Shadow_Leak writes that the Xiaomi 12S and Xiaomi 12S Pro will launch with different SoCs. Reputedly, the Xiaomi 12S will feature the Snapdragon 8 Gen 1, currently Qualcomm's flagship mobile chipset. In comparison, the leaker believes that the Xiaomi 12S Pro will rely on the Snapdragon 8 Gen 1 Plus, an upgraded version of the Snapdragon 8 Gen 1 that is rumoured to debut in devices from this summer onwards.