Why do the inscriptions on some statues and columns have certain letters in caps and others in lower case?

This is what is known as a chronogram. Notice that the letters in caps are C, D, I, L, M, V, and X – all Roman numerals. If you add up the number value of all of these letters, you get the date when the statue was erected. For example, AMore MatVrItas is deciphered as MMVI or 2006. There are also more complicated types – in a pure chronogram each word has a number and in a natural chronogram the numbers are in the correct order – but most Czech cases take the more basic form which is hard enough to write (try it yourself).