Define 'valuable security' and discuss its relevance in the context of the code in Indian Penal Code (IPC 1860) Section 30: “Valuable security” and their relevant Bharatiya Nyaya Sanhita 2023 (BNS 2023) code reference.

{'IPC Section': '29', 'IPC Heading': '“Document”', 'IPC Descriptions': ' Indian Penal Code, 1860 
29.
"Document" 
The word
"document" denotes any matter expressed or described upon any
substance by means of letters, figures, or marks, or by more than one of those
means, intended to be used, or which may be used, as evidence of that matter.
Explanation 1  It is immaterial by what means or upon what substance the
letters, figures or marks are formed, or whether the evidence is intended for,
or may be used in, a Court of Justice, or not. 
Illustrations
A writing expressing
the terms of a contract, which may be used as evidence of the contract, is a
document.
A cheque upon a banker
is a document.
A powerofattorney is
a document.
A map or plan which is
intended to be used or which may be used as evidence, is a document.
Explanation 2  Whatever is expressed by means of letters, figures or
marks as explained by mercantile or other usage, shall be deemed to be
expressed by such letters, figures or marks within the meaning of this section,
although the same may not be actually expressed. 
Illustration
A writes his name on
the back of a bill of exchange payable to his order. The meaning of the
endorsement, as explained by mercantile usage, is that the bill is to be paid
to the holder. The endorsement is a document, and must be construed in the same
manner as if the words "pay to the holder" or words to that effect
had been written over the signature.', 'BNS Section': '2(8)', 'BNS Heading': '“Document”', 'BNS description': 'The Bharatiya Nyaya Sanhita, 2023
 2. Definitions 
In this Sanhita, unless the context otherwise requires,
(8) "document" means any matter expressed or described upon any substance by means of letters, figures or marks, or by more than one of those means, and includes electronic and digital record, intended to be used, or which may be used, as evidence of that matter.
Explanation 1.It is immaterial by what means or upon what substance the letters, figures or marks are formed, or whether the evidence is intended for, or may be used in a Court or not.
Illustrations.
(a) A writing expressing the terms of a contract, which may be used as evidence of the contract, is a document.
(b) A cheque upon a banker is a document.
(c) A powerofattorney is a document.
(d) A map or plan which is intended to be used or which may be used as evidence, is a document.
(e) A writing containing directions or instructions is a document.
Explanation 2.Whatever is expressed by means of letters, figures or marks as explained by mercantile or other usage, shall be deemed to be expressed by such letters, figures or marks within the meaning of this section, although the same may not be actually expressed.
Illustration.
A writes his name on the back of a bill of exchange payable to his order. The meaning of the endorsement, as explained by mercantile usage, is that the bill is to be paid to the holder. The endorsement is a document, and shall be construed in the same manner as if the words "pay to the holder" or words to that effect had been written over the signature;'}