<sign >

::=

“+” | “-”

<digit >

::=

“0” | “1” | “2” | “3” | “4” | “5” | “6” | “7” | “8” | “9”

<digits >

::=

<digit ><digits > | <digit >

<factor >

::=

<digits >

<exponent >

::=

<sign ><digits > | <digits >

<simple-unit >

::=

<ATOM-SYMBOL > | <PREFIX-SYMBOL ><ATOM-SYMBOL[metric] >

<annotatable >

::=

<simple-unit ><exponent > | <simple-unit >

<component >

::=

<annotatable ><annotation >| <annotatable >| <annotation >| <factor >| “(”<term >“)”

<term >

::=

<term >“.”<component > | <term >“/”<component > | <component >

<main-term >

::=

“/”<term > | <term >

<annotation >

::=

“{”<ANNOTATION-STRING >“}”

Symbol (c/s)

Display Name

Print Symbol

value

Y

yotta 

Y 

1 × 1024 

Z

zetta 

Z 

1 × 1021 

E

exa 

E 

1 × 1018 

P

peta 

P 

1 × 1015 

T

tera 

T 

1 × 1012 

G

giga 

G 

1 × 109 

M

mega 

M 

1 × 106 

k

kilo 

k 

1 × 103 

h

hecto 

h 

1 × 102 

da

deka 

da 

1 × 101 

d

deci 

d 

1 × 10-1 

c

centi 

c 

1 × 10-2 

m

milli 

m 

1 × 10-3 

u

micro 

μ 

1 × 10-6 

n

nano 

n 

1 × 10-9 

p

pico 

p 

1 × 10-12 

f

femto 

f 

1 × 10-15 

a

atto 

a 

1 × 10-18 

z

zepto 

z 

1 × 10-21 

y

yocto 

y 

1 × 10-24 

Symbol (c/s)

Display Name

Print Symbol

value

Ki

kibi 

Ki 

1 × 10241

Mi

mebi 

Mi 

1 × 10242

Gi

gibi 

Gi 

1 × 10243

Ti

tebi 

Ti 

1 × 10244

Pi

pebi

Pi

1 × 10245

Ei

exbi

Ei

1 × 10246

Zi

zebi

Zi

1 × 10247

Yi

yobi

Yi

1 × 10248

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

m

meter 

m 

length 

yes

s

second 

s 

time 

yes

g

gram 

g 

mass 

yes

rad

radian 

rad 

plane angle 

yes

K

kelvin 

K 

temperature 

yes

C

coulomb 

C 

electric charge 

yes

cd

candela 

cd 

luminous intensity 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

10* 

the number ten for arbitrary powers 

10n 

no

10^ 

the number ten for arbitrary powers 

10n 

no

[pi] 

the number pi 

π 

no

% 

percent 

% 

no

[ppth] 

parts per thousand 

ppth 

no

[ppm] 

parts per million 

ppm 

no

[ppb] 

parts per billion 

ppb 

no

[pptr] 

parts per trillion 

pptr 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

mol 

mole 

mol 

amount of substance 

yes

sr 

steradian 

sr 

solid angle 

yes

Hz 

hertz 

Hz 

frequency 

yes

N 

newton 

N 

force 

yes

Pa 

pascal 

Pa 

pressure 

yes

J 

joule 

J 

energy 

yes

W 

watt 

W 

power 

yes

A 

ampère 

A 

electric current 

yes

V 

volt 

V 

electric potential 

yes

F 

farad 

F 

electric capacitance 

yes

Ohm 

ohm 

Ω 

electric resistance 

yes

S 

siemens 

S 

electric conductance 

yes

Wb 

weber 

Wb 

magnetic flux 

yes

Cel 

degree Celsius 

°C 

temperature 

yes

T 

tesla 

T 

magnetic flux density 

yes

H 

henry 

H 

inductance 

yes

lm 

lumen 

lm 

luminous flux 

yes

lx 

lux 

lx 

illuminance 

yes

Bq 

becquerel 

Bq 

radioactivity 

yes

Gy 

gray 

Gy 

energy dose 

yes

Sv 

sievert 

Sv 

dose equivalent 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

gon 

gon, grade 

□g 

plane angle 

no

deg 

degree 

° 

plane angle 

no

' 

minute 

' 

plane angle 

no

'' 

second 

'' 

plane angle 

no

l 

liter 

l 

volume 

yes

L 

liter 

L 

volume 

yes

ar 

are 

a 

area 

yes

min 

minute 

min 

time 

no

h 

hour 

h 

time 

no

d 

day 

d 

time 

no

a_t 

tropical year 

at 

time 

no

a_j 

mean Julian year 

aj 

time 

no

a_g 

mean Gregorian year 

ag 

time 

no

a 

year 

a 

time 

no

wk 

week 

wk 

time 

no

mo_s 

synodal month 

mos 

time 

no

mo_j 

mean Julian month 

moj 

time 

no

mo_g 

mean Gregorian month 

mog 

time 

no

mo 

month 

mo 

time 

no

t 

tonne 

t 

mass 

yes

bar 

bar 

bar 

pressure 

yes

u 

unified atomic mass unit 

u 

mass 

yes

eV 

electronvolt 

eV 

energy 

yes

AU 

astronomic unit 

AU 

length 

no

pc 

parsec 

pc 

length 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[c] 

velocity of light 

c  

velocity 

yes

[h] 

Planck constant 

h  

action 

yes

[k] 

Boltzmann constant 

k  

(unclassified) 

yes

[eps_0] 

permittivity of vacuum 

ε 0  

electric permittivity 

yes

[mu_0] 

permeability of vacuum 

μ 0  

magnetic permeability 

yes

[e] 

elementary charge 

e  

electric charge 

yes

[m_e] 

electron mass 

m e  

mass 

yes

[m_p] 

proton mass 

m p  

mass 

yes

[G] 

Newtonian constant of gravitation 

G  

(unclassified) 

yes

[g] 

standard acceleration of free fall 

g n  

acceleration 

yes

atm 

standard atmosphere 

atm 

pressure 

no

[ly] 

light-year 

l.y. 

length 

yes

gf 

gram-force 

gf 

force 

yes

[lbf_av] 

pound force 

lbf 

force 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

Ky 

Kayser 

K 

lineic number 

yes

Gal 

Gal 

Gal 

acceleration 

yes

dyn 

dyne 

dyn 

force 

yes

erg 

erg 

erg 

energy 

yes

P 

Poise 

P 

dynamic viscosity 

yes

Bi 

Biot 

Bi 

electric current 

yes

St 

Stokes 

St 

kinematic viscosity 

yes

Mx 

Maxwell 

Mx 

flux of magnetic induction 

yes

G 

Gauss 

Gs, G 

magnetic flux density 

yes

Oe 

Oersted 

Oe 

magnetic field intensity 

yes

Gb 

Gilbert 

Gb 

magnetic tension 

yes

sb 

stilb 

sb 

lum. intensity density 

yes

Lmb 

Lambert 

L 

brightness 

yes

ph 

phot 

ph 

illuminance 

yes

Ci 

Curie 

Ci 

radioactivity 

yes

R 

Roentgen 

R 

ion dose 

yes

RAD 

radiation absorbed dose 

RAD 

energy dose 

yes

REM 

radiation equivalent man 

REM 

dose equivalent 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[in_i] 

inch 

in

length 

no

[ft_i] 

foot 

ft

length 

no

[yd_i] 

yard 

yd

length 

no

[mi_i] 

mile 

mile

length 

no

[fth_i] 

fathom 

fth

depth of water 

no

[nmi_i] 

nautical mile 

n mile

length 

no

[kn_i] 

knot 

kn

velocity 

no

[sin_i] 

square inch 

in²

area 

no

[sft_i] 

square foot 

ft²

area 

no

[syd_i] 

square yard 

yd²

area 

no

[cin_i] 

cubic inch 

in³

volume 

no

[cft_i] 

cubic foot 

ft³

volume 

no

[cyd_i] 

cubic yard 

yd³

volume 

no

[bf_i] 

board foot 

fbm

volume 

no

[cr_i] 

cord 

cord

volume 

no

[mil_i] 

mil 

mil

length 

no

[cml_i] 

circular mil 

cmil

area 

no

[hd_i] 

hand 

height of horses 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[ft_us] 

foot 

ft (US survey)

length 

no

[yd_us] 

yard 

length 

no

[in_us] 

inch 

length 

no

[rd_us] 

rod 

length 

no

[ch_us] 

Gunter's chain, Surveyor's chain 

length 

no

[lk_us] 

link for Gunter's chain 

length 

no

[rch_us] 

Ramden's chain, Engineer's chain 

length 

no

[rlk_us] 

link for Ramden's chain 

length 

no

[fth_us] 

fathom 

length 

no

[fur_us] 

furlong 

length 

no

[mi_us] 

mile 

mi (US survey)

length 

no

[acr_us] 

acre 

area 

no

[srd_us] 

square rod 

area 

no

[smi_us] 

square mile 

mi² (US survey)

area 

no

[sct] 

section 

area 

no

[twp] 

township 

area 

no

[mil_us] 

mil 

length 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[in_br] 

inch 

length 

no

[ft_br] 

foot 

length 

no

[rd_br] 

rod 

length 

no

[ch_br] 

Gunter's chain 

length 

no

[lk_br] 

link for Gunter's chain 

length 

no

[fth_br] 

fathom 

length 

no

[pc_br] 

pace 

length 

no

[yd_br] 

yard 

length 

no

[mi_br] 

mile 

length 

no

[nmi_br] 

nautical mile 

length 

no

[kn_br] 

knot 

velocity 

no

[acr_br] 

acre 

area 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[gal_us] 

Queen Anne's wine gallon 

fluid volume 

no

[bbl_us] 

barrel 

barrel (US)

fluid volume 

no

[qt_us] 

quart 

liq qt (US)

fluid volume 

no

[pt_us] 

pint 

liq pt (US)

fluid volume 

no

[gil_us] 

gill 

gi (US)

fluid volume 

no

[foz_us] 

fluid ounce 

fl oz (US)

fluid volume 

no

[fdr_us] 

fluid dram 

fluid volume 

no

[min_us] 

minim 

fluid volume 

no

[crd_us] 

cord 

fluid volume 

no

[bu_us] 

bushel 

dry volume 

no

[gal_wi] 

historical winchester gallon 

dry volume 

no

[pk_us] 

peck 

dry volume 

no

[dqt_us] 

dry quart 

dry volume 

no

[dpt_us] 

dry pint 

dry volume 

no

[tbs_us] 

tablespoon 

volume 

no

[tsp_us] 

teaspoon 

volume 

no

[cup_us] 

cup 

volume 

no

[foz_m] 

metric fluid ounce 

fluid volume 

no

[cup_m] 

metric cup 

volume 

no

[tsp_m] 

metric teaspoon 

volume 

no

[tbs_m] 

metric tablespoon 

volume 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[gal_br] 

gallon 

gal (UK)

volume 

no

[pk_br] 

peck 

pk (UK)

volume 

no

[bu_br] 

bushel 

bushel (UK)

volume 

no

[qt_br] 

quart 

qt (UK)

volume 

no

[pt_br] 

pint 

pt (UK)

volume 

no

[gil_br] 

gill 

gi (UK)

volume 

no

[foz_br] 

fluid ounce 

fl oz (UK)

volume 

no

[fdr_br] 

fluid dram 

volume 

no

[min_br] 

minim 

volume 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[gr] 

grain 

mass 

no

[lb_av] 

pound 

mass 

no

[oz_av] 

ounce 

mass 

no

[dr_av] 

dram 

mass 

no

[scwt_av] 

short hundredweight, U.S. hundredweight 

mass 

no

[lcwt_av] 

long hunderdweight, British hundredweight 

mass 

no

[ston_av] 

short ton, U.S. ton 

mass 

no

[lton_av] 

long ton, British ton 

mass 

no

[stone_av] 

stone, British stone 

mass 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[pwt_tr] 

pennyweight 

mass 

no

[oz_tr] 

ounce 

mass 

no

[lb_tr] 

pound 

mass 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[lne] 

line 

length 

no

[pnt] 

point 

length 

no

[pca] 

pica 

length 

no

[pnt_pr] 

Printer's point 

length 

no

[pca_pr] 

Printer's pica 

length 

no

[pied] 

pied, French foot 

length 

no

[pouce] 

pouce, French inch 

length 

no

[ligne] 

ligne, French line 

length 

no

[didot] 

didot, Didot's point 

length 

no

[cicero] 

cicero, Didot's pica 

length 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

[degF] 

degree Fahrenheit 

°F 

temperature 

no

[degR] 

degree Rankine 

°R 

temperature 

no

[degRe] 

degree Réaumur 

°Ré 

temperature 

no

cal_[15] 

calorie at 15 °C 

cal15°C 

energy 

yes

cal_[20] 

calorie at 20 °C 

cal20°C 

energy 

yes

cal_m 

mean calorie 

calm 

energy 

yes

cal_IT 

international table calorie 

calIT 

energy 

yes

cal_th 

thermochemical calorie 

calth 

energy 

yes

cal 

calorie 

cal 

energy 

yes

[Cal] 

nutrition label Calories 

Cal 

energy 

no

[Btu_39] 

British thermal unit at 39 °F 

Btu39°F 

energy 

no

[Btu_59] 

British thermal unit at 59 °F 

Btu59°F 

energy 

no

[Btu_60] 

British thermal unit at 60 °F 

Btu60°F 

energy 

no

[Btu_m] 

mean British thermal unit 

Btum 

energy 

no

[Btu_IT] 

international table British thermal unit 

BtuIT 

energy 

no

[Btu_th] 

thermochemical British thermal unit 

Btuth 

energy 

no

[BTU] 

British thermal unit 

btu 

energy 

no

[HP] 

horsepower 

power 

no

TEX 

tex 

tex 

linear mass density (of textile thread) 

yes

[DEN] 

Denier 

den 

linear mass density (of textile thread) 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

m[H2O] 

meter of water column 

m H2O 

pressure 

yes

m[Hg] 

meter of mercury column 

m Hg 

pressure 

yes

[in_i'H2O] 

inch of water column 

in H2O 

pressure 

no

[in_i'Hg] 

inch of mercury column 

in Hg 

pressure 

no

[PRU] 

peripheral vascular resistance unit 

P.R.U. 

fluid resistance 

no

[wood'U] 

Wood unit 

Wood U. 

fluid resistance 

no

[diop] 

diopter 

dpt 

refraction of a lens 

no

[p'diop] 

prism diopter 

PD 

refraction of a prism 

no

%[slope] 

percent of slope 

% 

slope 

no

[mesh_i] 

mesh 

lineic number 

no

[Ch] 

Charrière, french 

Ch 

gauge of catheters 

no

[drp] 

drop 

drp 

volume 

no

[hnsf'U] 

Hounsfield unit 

HF 

x-ray attenuation 

no

[MET] 

metabolic equivalent 

MET 

metabolic cost of physical activity 

no

[hp'_X] 

homeopathic potency of decimal series (retired) 

X 

homeopathic potency (retired) 

no

[hp'_C] 

homeopathic potency of centesimal series (retired) 

C 

homeopathic potency (retired) 

no

[hp'_M] 

homeopathic potency of millesimal series (retired) 

M 

homeopathic potency (retired) 

no

[hp'_Q] 

homeopathic potency of quintamillesimal series (retired) 

Q 

homeopathic potency (retired) 

no

[hp_X] 

homeopathic potency of decimal hahnemannian series 

X 

homeopathic potency (Hahnemann) 

no

[hp_C] 

homeopathic potency of centesimal hahnemannian series 

C 

homeopathic potency (Hahnemann) 

no

[hp_M] 

homeopathic potency of millesimal hahnemannian series 

M 

homeopathic potency (Hahnemann) 

no

[hp_Q] 

homeopathic potency of quintamillesimal hahnemannian series 

Q 

homeopathic potency (Hahnemann) 

no

[kp_X] 

homeopathic potency of decimal korsakovian series 

X 

homeopathic potency (Korsakov) 

no

[kp_C] 

homeopathic potency of centesimal korsakovian series 

C 

homeopathic potency (Korsakov) 

no

[kp_M] 

homeopathic potency of millesimal korsakovian series 

M 

homeopathic potency (Korsakov) 

no

[kp_Q] 

homeopathic potency of quintamillesimal korsakovian series 

Q 

homeopathic potency (Korsakov) 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

eq 

equivalents 

eq 

amount of substance 

yes

osm 

osmole 

osm 

amount of substance (dissolved particles) 

yes

[pH] 

pH 

pH 

acidity 

no

g% 

gram percent 

g% 

mass concentration 

yes

[S] 

Svedberg unit 

S 

sedimentation coefficient 

no

[HPF] 

high power field 

HPF 

view area in microscope 

no

[LPF] 

low power field 

LPF 

view area in microscope 

no

kat 

katal 

kat 

catalytic activity 

yes

U 

Unit 

U 

catalytic activity 

yes

[iU] 

international unit 

IU 

arbitrary 

yes

[IU] 

international unit 

i.U. 

arbitrary 

yes

[arb'U] 

arbitary unit 

arb. U 

arbitrary 

no

[USP'U] 

United States Pharmacopeia unit 

U.S.P. 

arbitrary 

no

[GPL'U] 

GPL unit 

biologic activity of anticardiolipin IgG 

no

[MPL'U] 

MPL unit 

biologic activity of anticardiolipin IgM 

no

[APL'U] 

APL unit 

biologic activity of anticardiolipin IgA 

no

[beth'U] 

Bethesda unit 

biologic activity of factor VIII inhibitor 

no

[anti'Xa'U] 

anti factor Xa unit 

biologic activity of factor Xa inhibitor (heparin) 

no

[todd'U] 

Todd unit 

biologic activity antistreptolysin O 

no

[dye'U] 

Dye unit 

biologic activity of amylase 

no

[smgy'U] 

Somogyi unit 

biologic activity of amylase 

no

[bdsk'U] 

Bodansky unit 

biologic activity of phosphatase 

no

[ka'U] 

King-Armstrong unit 

biologic activity of phosphatase 

no

[knk'U] 

Kunkel unit 

arbitrary biologic activity 

no

[mclg'U] 

Mac Lagan unit 

arbitrary biologic activity 

no

[tb'U] 

tuberculin unit 

biologic activity of tuberculin 

no

[CCID_50] 

50% cell culture infectious dose 

CCID50 

biologic activity (infectivity) of an infectious agent preparation 

no

[TCID_50] 

50% tissue culture infectious dose 

TCID50 

biologic activity (infectivity) of an infectious agent preparation 

no

[EID_50] 

50% embryo infectious dose 

EID50 

biologic activity (infectivity) of an infectious agent preparation 

no

[PFU] 

plaque forming units 

PFU 

amount of an infectious agent 

no

[FFU] 

focus forming units 

FFU 

amount of an infectious agent 

no

[CFU] 

colony forming units 

CFU 

amount of a proliferating organism 

no

[IR] 

index of reactivity 

IR 

amount of an allergen calibrated through in-vivo testing using the Stallergenes® method. 

no

[BAU] 

bioequivalent allergen unit 

BAU 

amount of an allergen calibrated through in-vivo testing based on the ID50EAL method of (intradermal dilution for 50mm sum of erythema diameters 

no

[AU] 

allergen unit 

AU 

procedure defined amount of an allergen using some reference standard 

no

[Amb'a'1'U] 

allergen unit for Ambrosia artemisiifolia 

Amb a 1 U 

procedure defined amount of the major allergen of ragweed. 

no

[PNU] 

protein nitrogen unit 

PNU 

procedure defined amount of a protein substance 

no

[Lf] 

Limit of flocculation 

Lf 

procedure defined amount of an antigen substance 

no

[D'ag'U] 

D-antigen unit 

procedure defined amount of a poliomyelitis d-antigen substance 

no

[FEU] 

fibrinogen equivalent unit 

amount of fibrinogen broken down into the measured d-dimers 

no

[ELU] 

ELISA unit 

arbitrary ELISA unit 

no

[EU] 

Ehrlich unit 

Ehrlich unit 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

Np 

neper 

Np 

level 

yes

B 

bel 

B 

level 

yes

B[SPL] 

bel sound pressure 

B(SPL) 

pressure level 

yes

B[V] 

bel volt 

B(V) 

electric potential level 

yes

B[mV] 

bel millivolt 

B(mV) 

electric potential level 

yes

B[uV] 

bel microvolt 

B(μV) 

electric potential level 

yes

B[10.nV] 

bel 10 nanovolt 

B(10 nV) 

electric potential level 

yes

B[W] 

bel watt 

B(W) 

power level 

yes

B[kW] 

bel kilowatt 

B(kW) 

power level 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

st 

stere 

st 

volume 

yes

Ao 

Ångström 

Å 

length 

no

b 

barn 

b 

action area 

no

att 

technical atmosphere 

at 

pressure 

no

mho 

mho 

mho 

electric conductance 

yes

[psi] 

pound per sqare inch 

psi 

pressure 

no

circ 

circle 

circ 

plane angle 

no

sph 

spere 

sph 

solid angle 

no

[car_m] 

metric carat 

ctm 

mass 

no

[car_Au] 

carat of gold alloys 

ctAu 

mass fraction 

no

[smoot] 

Smoot 

length 

no

[m/s2/Hz^(1/2)] 

meter per square seconds per square root of hertz 

amplitude spectral density 

no

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

bit_s 

bit 

bits 

amount of information 

no

bit 

bit 

bit 

amount of information 

yes

By 

byte 

B 

amount of information 

yes

Bd 

baud 

Bd 

signal transmission rate 

yes

Symbol (c/s)

Display Name

Print Symbol

Kind of Quantity

Metric

{tot} 

particles total count 

tot. 

number 

no

{tbl} 

tablets 

tbl. 

number 

no

{rbc} 

red blood cell count 

R.B.C. 

number 

no

g.m/{H.B.} 

gram meter per heartbeat 

g· m/H.B. 

proportional to ventricular stroke work 

no

gf.m/{H.B.} 

gram-force meter per heartbeat 

gf· m/H.B. 

ventricular stroke work 

no

kg{wet'tis} 

kilogram of wet tissue 

kg(wet tissue) 

mass 

no

mg{creat} 

milligram of creatinine 

mg(creat.) 

mass 

no