ANSI/IEEE Std 991-1986 Recommends any of three characters for negation:
"not" symbol, which I can't render in ASCII, and I seem to remember being used in Algol (and perhaps PL1).
The latter looks like a wide overstrike, with a short vertical descender on the right end.
From: Shepard Bob-G14751 [mailto:Bob.Shepard@motorola.com]
Sent: Tuesday, 23 January, 2001 4:54 PM
To: 'Philip Decker'
Subject: RE: Ref. Doc. for "#" for active low
It seems to be an Intel practice to use the "#" postfix to
designate active low signals. Intel developed the PCI and
their practice stuck. It's a good thing PCI wasn't developed
by DEC so we don't use "_l".
What symbol is recommended in your "IEEE Standard for Logic
Circuit Diagrams"? Does it apply to text publications as
Senior Staff Engineer
Monterey Design Center
Motorola Computer Group
12 Upper Ragsdale Drive
Monterey, CA 93940
Both the PCI and the PCMCIA specs use "#" as the trailing
character for the names of active low signals. What standard
or spec defines that usage? Not ANSI/IEEE 991-1986.
Philip Decker, Director of Engineering
Wave Wireless Networking