Is the mp3 lyrics format .irc or .Lrc?

Hai frnds i have a doubt.Its so annoying that the i and L on my mobile is indistinguishable.When the 'i' is in capital letter form, it looks like this 'I'.When the L is in small letter form it luks lyk ths 'l', thats same like the 'i',in capital letter form.How the *** am i supposed 2 know the difference.Ok so i have a music player for my fone whch plays lyrics along wth d song, so it has a format,i dnt know whthr the format extension is .irc or .Lrc