Reference

Review printable and control ASCII characters along with their decimal, hexadecimal, octal and binary values for low-level debugging.

Use the cron editor as a practical reference to interpret fields, presets and upcoming runs when documenting scheduled tasks.

Look up DNS record types—address, mail, alias, zone, service, and security—with their name, what they are for, and examples, when configuring domains or diagnosing resolution.

Search characters, symbols and HTML entities to copy their correct representation when working with web content or documentation.

Look up HTTP status codes by family to understand API, server and browser responses during debugging or technical documentation.

Search by number or service among the TCP and UDP ports most used in servers, networks and development: web, email, databases, remote access, VPN, containers and more, with the unencrypted ones flagged.

Use the IEEE OUI registry as a reference to translate the prefix of any MAC address into the manufacturer's name, and to see whether the address is unicast or multicast and whether it is globally assigned or locally administered.

Find MIME types and associated extensions to configure HTTP responses, file validations, uploads and content metadata.

Use the pci.ids catalog as a reference to translate any PCI Vendor ID and Device ID to the chip name, and the subsystem to the specific board model.

Use the usb.ids catalog as a reference to translate any USB Vendor ID and Product ID to the manufacturer and product name, with the version and date of the consulted catalog.

Calculate chmod permissions for Unix and Linux by checking boxes for user, group, and others, include the special bits setuid, setgid, and sticky, and get the octal number, symbolic notation, and chmod command ready to copy.