[metadata]
id = "PRE30-C"
type = "rule"
category = "PRE"
number = 30
title = "Do not create a universal character name through concatenation"
description = """
The C Standard supports universal character names that may be used in
identifiers, character constants, and string literals to designate characters
that are not in the basic character set. The universal character
name\Unnnnnnnndesignates the character whose 8-digit short identifier (as
specified by ISO/IEC 10646) isnnnnnnnn. Similarly, the universal character
name\unnnndesignates the character whose 4-digit short identifier isnnnn(and
whose 8-digit short identifier is0000nnnn). The C Standard, 5.1.1.2, paragraph 4
[ISO/IEC 9899:2024], says See alsoundefined behavior 3.
"""
severity = "Low"
likelihood = "Unlikely"
priority = "P2"
level = "L3"
cert_version = "2016 Edition (Wiki)"
last_modified = "Oct 29, 2025"
[rules.cert_c.PRE30-C]
enabled = true
[references]
wiki = "https://wiki.sei.cmu.edu/confluence/display/c/PRE30-C.+Do+not+create+a+universal+character+name+through+concatenation"