Rapid-fire answers

5-pin (PCB mount) switches have two extra plastic legs on the bottom for stability. 3-pin (Plate mount) switches lack these legs. 5-pin switches can be converted to 3-pin by cleanly clipping the extra plastic legs with flush cutters. A 3-pin switch cannot be converted to 5-pin.

The switch itself is merely a component. Hot-swap capability is determined by the keyboard's PCB (Printed Circuit Board). If the PCB features Kailh or Gateron hot-swap sockets, you can pull and replace switches without a soldering iron. If it is a standard soldered PCB, you must desolder the old switches first.

Actuation force is the amount of pressure (measured in grams, e.g., 45g, 62g) required to push the stem down far enough to register a keypress. 'Bottom out force' is the heavier weight required to press the stem all the way down. Operators should select lighter forces (45g) for gaming and heavier forces (60g+) for heavy-handed typing to prevent accidental keystrokes.

It is highly advised against lubricating the tactile legs or the click-mechanism of a clicky switch (like Cherry MX Blue or Kailh Box Jade). Lube will dampen the acoustic click and often turn a clicky switch into an inconsistent, mushy tactile switch. You may lube the springs to prevent ping, but avoid the stem legs entirely.

SMD (Surface-Mount Device) LEDs are flat lights soldered flat on the PCB under the switch. An SMD-compatible switch has a large cutout or a clear plastic window in the bottom housing to allow that light to shine upward through the switch structure. Solid black bottom housings will block SMD light.

No switch is 100% silent. Silent switches (e.g., Cherry Silent Red, Boba U4) incorporate tiny rubber dampening pads on the stem rails. These pads cushion the stem when it hits the bottom housing and when it returns to the top housing, drastically reducing the high-frequency plastic clack. They are significantly quieter, emitting a low dull thud, but not totally silent.

A term for taking parts from two or more different switch models to create a custom hybrid. The most famous is the "Holy Panda," originally created by putting a Halo True/Clear tactile stem inside an Invyr Panda linear housing, resulting in a unique, massive tactile bump.

When using high-quality synthetic lubricants like Krytox 205g0 or Tribosys 3203, a properly lubed switch should retain its smooth characteristics for 3 to 5 years of heavy use before reapplication might be considered. The lubricant does not easily degrade, but can migrate off the rails over millions of actuations.