It is meaningless because they are an invalid arrangement of Roman numerals.
17th May, 1990 would be XVII. V. MCMCX in Roman numerals.
1990
In todays notation of Roman numerals: XXIV-VI-MCMXC
In todays notation of Roman numerals: VIII-V-MCMXC
The date 18-06-1990 in Roman numerals would be XVIII.VI.MCMXC
It is meaningless because they are an invalid arrangement of Roman numerals.
17th May, 1990 would be XVII. V. MCMCX in Roman numerals.
1990
In todays notation of Roman numerals: XXIV-VI-MCMXC
In todays notation of Roman numerals: VIII-V-MCMXC
The date 15-04-1990 can be represented by the Roman numerals XV.IV.MCMXC
In today's notation of Roman numerals: X-XIV-MCMXC
In today's arrangement of Roman numerals: XIV-II-MCMXC
In today's notation of Roman numerals: VIII-X-MCMXC
XII.XXV.MCMXC
i / viii / mcmxc