The string "" appears to refer to Windows 10 version 1809 (Build 17763.13), also known as the October 2018 Update .
The final "13" is the most nuanced part. In the context of the kernel, this typically refers to the or the cumulative update (CU) number . For example: kernel os 1809 13
Below is a based on the most probable interpretation: Windows 10/Server 2019, OS Build 17763, with specific reference to kernel changes as of update KB4512578 (September 2019). The string "" appears to refer to Windows