TZ
Explanation:
The TZ environment variable is used to change the time zone for the commands run from within the environment variable's scope. It specifies the name of a time zone as defined in the /usr/share/zoneinfo directory or a custom time zone in the POSIX format12. The TZ variable can be set either globally in a shell profile file or locally in a shell session. For example, to set the time zone to America/New_York for the current shell session, one can use the following command:
export TZ=America/New_York
To verify the change, one can use the date command to display the current date and time according to the TZ variable. The TZ variable can also be used to run a single command with a different time zone without affecting the system's time zone. For example, to run the date command with the Asia/Tokyo time zone, one can use the following syntax:
TZ=Asia/Tokyo date
The TZ variable is useful for testing how applications behave in different time zones or for displaying the time in different locations34. References:
* How to Set or Change the Time Zone in Linux | Linuxize
* Linux / UNIX: TZ Environment Variable - nixCraft
* Get Current System Time Zone in Linux | Baeldung on Linux
* Setting the TZ Environment Variable on Linux | InterSystems Developer

I

The configuration file for the OpenSSH server is called sshd_config. It is typically located in /etc/ssh on most
*NIX systems, but is /etc/sshd_config in the case of MacOS X and perhaps other systems. OpenSSH has two different sets of configuration files: one for client programs (ssh, scp, and sftp) and one for the server daemon (sshd). System-wide SSH configuration information is stored in the /etc/ssh/ directory1. References: 1: Where is the configuration file for OpenSSH server?

xorgconf
Explanation:
The default name of the configuration file for the Xorg X11 server is xorg.conf. This file is used to store initial setup for X, such as settings for video cards, monitors, input devices, and other options. The Xorg X11 server is a display server that uses a configuration file called xorg.conf and files ending in the suffix .conf for its initial setup1. The xorg.conf file is typically located in /etc/X11/xorg.conf, but its location may vary across operating system distributions2. The xorg.conf file is not mandatory, as the Xorg X11 server can automatically configure most hardware and settings. However, it can be created and edited manually if needed3. Reference:
Xorg - ArchWiki
xorg.conf - Wikipedia
How to Configure X11 in Linux: 10 Steps (with Pictures) - wikiHow

The file /etc/resolv.conf is the configuration file for the DNS resolver, which translates domain names to IP addresses by querying the DNS servers. The file supports several keywords that provide various types of resolver information. Two of the keywords that can be used in /etc/resolv.conf are:
* nameserver: This keyword specifies the IP address of the DNS server that the resolver can query against.
Up to three nameservers can be configured, and the resolver will try them in order until one responds or all fail.
* search: This keyword specifies a list of search domains that the resolver will append to the domain name when performing a query. For example, if the search list is example.com example.net, and the resolver queries for host, it will try host.example.com and host.example.net in order. The search list can have up to six domains, with a maximum of 256 characters in total.
The other keywords in the question are not valid for /etc/resolv.conf. The file does not support any keywords for substitution, lookup, or method. However, there are other keywords that can be used, such as:
* domain: This keyword specifies the local domain name of the system. It is mutually exclusive with the search keyword, and only one instance of either can be used.
* options: This keyword specifies various options that modify the behavior of the resolver. For example, the option rotate can be used to rotate the nameservers in a round-robin fashion, instead of trying them in order. Multiple options can be specified, separated by spaces.
References:
* 3: The /etc/resolv.conf File | Baeldung on Linux
* 1: /etc/resolv.conf - QNX
* 4: Chapter 33. Manually configuring the /etc/resolv.conf file