Usually, password account format is username:password (seperated by “:”) unless the post already indicates the word username (u: or l:) and password (p:).

For Example

http://www.xxx.com
abcdef:123456
u:abcdef
p:123456
l:abcdef
p:123456

at here, the website is www.xxx.com, username is abcdef, password is 123456

one more format is http://username:password@website

For Example

http://123456:abcdef@www.xxx.com/members/

at here, the website is www.xxx.com/members, username is 123456, password is abcdef