A recent phishing technique is to register domain names with international Unicode characters that look like English characters. The URL will visually look correct, but it will be a different website which often contains malicious content. Puny code is a representation of Unicode with the limited ASCII character subset used for Internet host names.
The Firefox web browser does not provide an indication that a domain name is using look-alike Unicode characters.
These instructions will enable showing long names when the domain names have Unicode characters.
Open a new tab in Firefox and enter this in the address bar, then press the button to proceed:
Search for punycode:
Right-click on the IDN_show_punycode:
Toggle the setting to true: