I heard an interesting thing, which is that in Philippines, the common wedding style is a civil wedding. I know the word of a civil wedding. But I didn't know that even if it is a civil wedding a witness is necessary, if the couple visit a city hall without a witness, the mayor becomes their witness.
Here in Japan, there are some wedding styles, a church style, a shrine style, a temple style, or a civil style. Probably all of them have witnesses, such as a minster price, a flamen, a monk or participants (in Japan the witness of a civil wedding is usually the participants.)
However all of them are simply a formality (if they have their own religion and the wedding is done according to the religion, it's not a formality. It's meaningful.)
The couple just submit a piece of paper saying they're married to the city hall, and the couple are registered as a married couple. So if the couple don't want to hold their wedding ceremony they don't need to do it. These days some couple don't do that. However when they fill up the paper to marry, there are two places where two witnesses write their signature on the paper. In my daughter's case my husband and her mother-in-law did it. (Unfortunately her mother-in-law has divorced.) though we didn't write our signature at the same time. They visited us and her mother-in-law in turn to get our signature.
I wrote this report as my note.