PCO stands for Potential Change Order (construction management). Suggest new definition. This definition appears somewhat frequently and is found in the following Acronym Finder categories: 1  Business, finance, etc.
Quick Answer. The Roman numeral XIX is the number 19. X is the number 10, and I is the number one. When a lower number is placed in front of a larger number, it indicates subtraction; IX is the same as 10 minus one, which equals nine. The Ancient Romans used different letters to represent numbers.
For example, the hebrew letters of Caesar Nero would sum to 666. The roman numerals in Ellen Gould White add to 666 (interpreting W as VV and U as V). If you use the code A=101, B=102, etc, then Hitler will add up to 666.or example, the hebrew letters of Caesar Nero would sum to 666. The roman numerals in Ellen Gould White add to 666 (interpreting W as VV and U as V). If you use the code A=101, B=102, etc, then Hitler will add up to 666.