CurlySMILES annotation dictionary key: i

The lower-case single character i is used as an annotation dictionary key that points to one or more other atomic nodes within a CurlySMILES notation. For each component (subnotation) of a CurlySMILES notation, atomic nodes are counted from left-to right by starting with number 1 at the first atom.
The value of i is composed by entries, which can be in any of the following formats: any of the following

Format	Meaning
n	single integer pointing to an atomic node by taking atomic node with number 1 as a reference
n-m	integer range (n<m) pointing to consecutive atomic nodes by taking atomic node with number 1 as a reference
-n	negative integer pointing to an atomic node by taking the anchor atom as a reference and formally moving to the left by n nodes

By default, the numbers of an entry refer to the atoms in the same component in which their anchor atom is located. To point to atoms of another component, the character # followed by the component number is appended to the entry. Multiple entries a separated by semicolon.
For example, if i=2-4,-3,7#1 is a key/value pair occurring in an annotation anchored at the ninth atom of the second component, then i is pointing to atoms 2, 3, 4, and 6 in this component and to atom 7 in the first component.

The following notation, which encodes a cyclic dimer of two benzoic acid molecules built by intermolecular hydrogen bonding, illustrates the use of i in a multi-component CurlySMILES notation:

c1ccccc1C(=O)O{!Hi=3#2}.O{!Hi=8#1}C(=O)c1ccccc1

The annotation {!Hi=3#2} at the hydroxy group in the first component indicates that the group's H-acceptor atom is the third atom in the second component. The annotation {!Hi=8#1} at the hydroxy group in the second component indicates that the acceptor atom is the eighth atom in the first component.

Format of an annotation:
{AMk₁=v₁;k₂=v₂;...;k_n=v_n}
where
AM is an annotion marker,
and
k_i=v_i is a key/value pair.