Explanation of notation

Syntax description language

Last updated 24-9-2006

Notation	Explanation	Example	Meaning	Remarks
Applicable to the syntax column only:
(.)	For administration only	(B)1	Number B1, but on signposts only '1' appears
In the syntax column and the system explanation:
[..]	variable string	[2468]	2, 4, 6 or 8
[.-.]	digit or letter range	[2-4]	2, 3 or 4	A dash has to be taken literally if it is used in a different context than a range.
.-.	numerical range	A1329-31	A1329, A1330 and A1331
{.}	optional string	{[ab]}	Optional letter a or b
.|.	separator for variables consisting of more than one character	[0-9][RD|LN]	A digit followed by either RD or LN	Also used between { } brackets
<.-.>	amount of times	[0-9]<1-2>	1 or 2 digits
^	superscript	[0-9]<1-2>^a	1 or 2 digits with superscript suffix a
'.'	literal (for special characters []{}<>();*)	'('M')'	Literal string '(M)'
`.`	reference to object defined somewhere else	`suffix`	reference to suffix
;	list separator (can also be used between brackets)	M1;M2	Numbers M1 and M2
In the system explanation only:
*	any number of times	[0-9]*	any number of digits
.-d	number of digits	3-d	3-digit numbers
x,y,z,u,v	digit variables	xxy	3-digit number of which the first two digits are the same	depending on context
	number variables	CRx	CR followed by some number
(.)	single digit separation	x(x+1)	12, 23, 34 etc.
ord(.)	ordinal function for letters	ordinal number for letters in the standard Roman alphabet, e.g. ord(A)=1, ord(B)=2, ord(K)=11. For two of the same letters, numbering continues after 26, e.g. ord(AA)=27, ord(AE)=31. Also, ord(AAA)=53 etc.
Numbers can not begin with 0, unless this is mentioned explicitly ('trailing zeroes').
More complicated examples:
A[2-4][0-9]<1-2>		A number with 2 or 3 digits beginning with 2, 3 or 4
r10[1-9]		Italicised numbers r101-r109 (r is never used as a variable)
A[0-9]<1-4>{'('M')'}		A numbers with 1 to 4 digits and an optional suffix '(M)'
B[1-5][0-9]<2>{[a-z]<1-2>}		3-digit B numbers beginning with 1, 2, 3, 4 or 5 and an optional 1- or 2-letter (lowercase) suffix
[A-F][A-C][0-9]<2>		Two capital letters of which the first is A-F and the second is A, B or C and two digits
x(x+1)[1-8]		Numbers of the form 121, 122, ..., 128, 231, 232, ..., 238 etc.
[NS][0-9]<2>[RD|LN]		N or S followed by two digits followed by RD or LN (note that [RDLN] would mean R, D, L or N, while [RD|LN] means either RD or LN)
FR[0-9]<2-4>{[A-T]|-[01]}		FR followed by 2 to 4 digits possibly followed by a letter A, B, ... or T or a dash and a 0 or 1
Colours
yellow	Information not very reliable
red	Pure guess

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