Thank you very much @ whispera I also checked Saunders Q & A page 351 and saw that an X mark would suffice if the client cannot write. It's just that, I had my clinical experience in a certain unit and they asked me to get the fingerprint of the client instead. That's why I'm confused.
Please help me. If the client is illiterate but competent to give consent, can i get his fingerprints instead? I just want to hear an opinion and not a legal advice.