Search notes:

/proc/sys/fs/binfmt_misc/

binfmt_misc stands for Miscellaneous Binary Format. It allows a user-mode application to register executable file formats that they can handle with the kernel.
The binfmt_misc functionality is used, for example, by

Files found under /proc/sys/fs/binfmt_misc

File's I've found under /proc/sys/fs/binfmt_misc include
register
status
WSLInterop Related to Windows Subsystem for Linux

Checking if binfmt_misc is enabled

$ cat /proc/sys/fs/binfmt_misc/status
enabled

Registering handlers

Handlers can be registered by writing into /proc/sys/fs/binfmt_misc/register.

See also

/proc/sys/fs/binfmt_misc/WSLInterop
The kernel source file fs/binfmt_misc.c

Links

Wikipedia: binfmt_misc
Kernel sourcet tree: Documentation/admin-guide/binfmt-msc.rst

Index

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/Linux/fh...', 1759612294, '216.73.216.149', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/Linux/fhs/proc/sys/fs/binfmt_misc/index(75): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78