Unicode Public Review Issue #96 talks about joiners, an important topic for Sinhala Unicode.
It proposes a solution to a possible security issue.
It shows how to solve it right, and also how to "solve" it wrong, by using pictures to show consequences in each case.
For example, PR-96 has some Sinhala text examples to show how a correct solution will render correct Sinhala text, and how an incorrect "solution" (e.g.: excluding joiners entirely) would render it incorrectly.
Here is a summary of PR-96:
Therefore, PR-96 is not just criticism. It is constructive criticism.
PR-96 has included some text samples. In these examples:
When the proposal in PR-96 is adhered: