What is the exact spelling for Shivaratri? There are nearly a dozen English spelling of Shivaratri in vogue on the internet and in print media. It is very difficult to make Search Engine like Google, Ask, Yahoo etct to understand that they all mean the same thing.
Shivaratri
Shivratri
Sivaratri (this spelling has a macron on top of S)
Mahashivaratri
Mahashivratri
Mahasivratri
Maha Shivaratri
Maha Shivratri
Maha Sivratri
Shivratri
Sivaratri (this spelling has a macron on top of S)
Mahashivaratri
Mahashivratri
Mahasivratri
Maha Shivaratri
Maha Shivratri
Maha Sivratri
Some more spelling variations are there but they are not relevant as they appear rarely in online newspapers and websites and are mostly typos.
Update - Today the different spellings are understood by search engines and they all will take you to Shivratri. Earlier it was not the case. Spellings were a big problem for Hindu religion writers as they had to use different types of spellings to make the search engines understand that they all meant the same thing.