add new SI prefixes; add binary prefixes

1 files changed, 43 insertions, 3 deletions

diff --git a/si.7 b/si.7
index a37e07f..f71876c 100644
--- a/si.7
+++ b/si.7
@@ -1,4 +1,4 @@
-.Dd $Mdocdate: April 2 2022  $
+.Dd $Mdocdate: May 22 2024  $
 .Dt SI 7
 .Os
 .Sh NAME
@@ -15,12 +15,16 @@ section are from NIST SP 811,
 .Em NIST Guide for the Use of the International System of Units (SI) ,
 2008,
 .Lk https://www.nist.gov/pml/special-publication-811 .
+
+The IEC binary prefixes are defined in ISO/IEC 80000-13.
 .Sh PREFIXES
 .TS
 allbox tab( );
 c | c | c || c | c | c
 l c r || l c r.
 Name Prefix Power Name Prefix Power
+quetta Q 30 quecto q -30
+ronna R 27 ronto r -27
 yotta Y 24 yocto y -24
 zetta Z 21 zepto z -21
 exa E 18 atto a -18
@@ -32,6 +36,37 @@ kilo k 3 milli m -3
 hecto h 2 centi c -2
 deka da 1 deci d -1
 .TE
+
+.Sh BINARY PREFIXES
+Binary prefixes multiply a unit by a power of 2. They not a part of the
+SI system. Most people will say
+.Dq kilobyte
+instead of
+.Dq kibibyte ,
+.Dq megabyte
+instead of
+.Dq mebibyte ,
+and so on. Mac OSX and Linux utilities commonly report
+units using the binary prefixes
+(
+.Dq KiB ,
+.Dq MiB ,
+etc).
+.TS
+allbox tab( );
+c | c | c
+l c r.
+Name Prefix Power Related
+kibi Ki 10 kilo
+mebi Mi 20 mega
+gibi Gi 30 giga
+tebi Ti 40 tera
+pebi Pi 50 peta
+exbi Ei 60 exa
+zebi Zi 70 zetta
+yobi Yi 80 yotta
+.TE
+
 .Sh BASE UNITS
 .TS
 allbox;
@@ -46,6 +81,7 @@ temperature	kelvin	K	\(*H
 luminosity	candela	cd	J
 Unitless	=	1	=
 .TE
+
 Unitless quantities (like indices of refraction) are usually written
 with no symbol at all, or with a conventional symbol, like
 .Dq rad
@@ -106,6 +142,7 @@ T{
 catalytic activity
 T}	katal	kat	mol s⁻¹	=
 .TE
+
 The equivalent units for pressure do not appear in the source.
 .Sh SAMPLE OF OTHER DERIVED UNITS
 .TS
@@ -139,7 +176,8 @@ radiant intensity
 T}	W sr⁻¹	kg m² s⁻³
 radiance	W sr⁻¹ m⁻²	kg s⁻³
 .TE
-The source gives more examples.
+
+The sources give more examples.
 .Sh NON-SI UNITS ACCEPTED FOR USE IN SI
 .TS
 allbox;
@@ -171,6 +209,7 @@ T}	neper	Np	natural log
 \^	bel	B	base-10 log
 \^	decibel	dB	1 dB = 10⁻¹ B
 .TE
+
 .Sh NOT-ACCEPTABLE NON-SI UNITS STILL IN USE
 .TS
 allbox;
@@ -189,5 +228,6 @@ T{
 magnetic flux density
 T}	gauss	G OR Gs	1 G = 100 μT
 .TE
+
 .Sh INFO
-This file is public domain. Manual page version 1.0.
+This file is public domain. Manual page version 2.0.