Why is this an issue?
Control characters (e.g., tabs or carriage returns) are not visible to maintainers, so they should be escaped.
Noncompliant code example
const char* foo = "A B"; // Noncompliant: contains a tabulation
const char* foo = "A\tB"; // Compliant: use escaped value
This rule does not raise issues in raw string literals since they have no escape character mechanism.