What type of rectangular chip is this? And how does one even know how to identify chips on boards?
It is actually a big problem. Often the same part is marked differently by different manufacturers an most of the 'short' markings have nothing to do with the actual component part number. For example the popular BC817 is marked 6A, 6B, 6C or 6D (depending on the hFE bin) plus an unspecified manufacturer coder. This for NXP. Onsemi instead adds a date code. Infineon adds an s
In short it's a mess. There are some sites online listing some common markings but usually I have been unlucky. These day you are lucky if there is an useable pin 1/cathode identifier, in fact.