The discussion centers on the character limitations for Wi-Fi usernames and passwords, highlighting that these restrictions can vary based on the web browser and Wi-Fi Access Point (WAP) being used. While browsers are generally well-documented, obtaining specific details from WAP manufacturers can be more challenging. The conversation emphasizes that a strong password should be long and ordinary rather than relying on obscure characters, as this is more effective against serious hacking attempts. According to the IEEE 802.11 standard, all characters traditionally used in writing systems are allowed, but in practice, many routers only accept a specific range of ASCII characters, excluding spaces. The relevant ASCII characters include numbers, letters, and various symbols, but users should verify the specific character set supported by their router.