or Rooms? or just a sheet dedicated to the EMC shielded area? I've seen just polygons used to communicate "doghouse" or "tin can" or "shielded", was trying to move towards something more formalized. Dashed box with EMC shield seems to work as then you can have an impedance blanket inside of that. Others have suggested put it on a sheet by itself and add freeform text. To be clear, I'm interested in communicating the design intent in the schematic, much like one would use a Chassis GND symbol, not wait for layout.

I see request for review of schematics on r/PrintedCircuitBoard r/kicad, r/altium , and I get schematics to review and I will see deviations from IEEE 315/ ANSI Y32.2. Is there a reason designers have that they cannot or will not follow ANSI Y32.2? I sometimes see IC# for refdes instead of U#. CN# for connectors in Asia, sometimes. I see where IEC 81346 could come into the situation where someone has industrial training, so they want to use K# for the processor, but that standard is for plant documentation, not for PCB schematics. I am not seeing a international standard in Europe or Asia which competes wiht ANSI Y32.2/IEEE 315. It would be interesting if in these groups where a review is asked for that it meet IEEE 315. What do you all think? is it practical? correct? Is this a good foundation to teach students and new designers using r/Kicad or r/Altium and other EDA tools? TIA

For board-level work, IEEE 315 conventions have some real advantages worth weighing:

• Tool alignment — EDA libraries, schematic linters, BOM generators, and ECAD-MCAD bridges are built around these conventions
• Vendor consistency — IC manufacturer reference designs use them across regions
• Readability across teams — a designer in Taipei, Stuttgart, or Austin can pick up the schematic and know R10 is a resistor without consulting the BOM
• AI and automation compatibility — automated tools expect schematic data in certain standard ways, IEEE 315, IEEE 1149.1, IPC 7351B etc to classify components correctly

For systems-level work — control cabinets, plant integration, machinery documentation — IEC 81346 serves its purpose well but it wasn't intended for PCB electrical schematics.

A working refdes set for PCB schematics from IEEE 315

Component	Refdes
Resistor	R
Capacitor	C
Inductor	L
Diode (any kind, including LED)	D
Transistor	Q
Integrated circuit (any kind)	U
Crystal / oscillator	Y
Fuse	F
Connector (jack / plug)	J / P
Switch	S
Transformer	T
Relay	K
Battery	BT
Test point	TP
Antenna	E
Ferrite bead	FB

Aware of legacy CR-for-diode and X-for-crystal variants from mil-aero work — those have their own context and history.