What do the highest-priority rules for local administration in udev reside?

The highest-priority rules for local administration in udev reside in the directory associated with the system's configuration file hierarchy, specifically in /etc/udev/rules.d. This directory is used for custom rules that system administrators can define to manage devices and their attributes dynamically. By placing rules in /etc/udev/rules.d, administrators can ensure that these local rules take precedence over the default rules provided by the system, which are typically found in the /usr/lib/udev/rules.d or /lib/udev/rules.d directories.

The rationale behind this structure is to separate the default rules, which are part of the package installations and may be overwritten during updates, from the custom rules that an administrator might define. Thus, placing rules in /etc/udev/rules.d allows for effective local modification and management of device handling without disrupting the default behavior of the system. This approach supports both system integrity and individual customization, enabling better control over how devices are managed upon connection to the system.