This section includes rules regarding hyphens, commas, parentheses and quotations. Ambiguities can often be resolved by the selective use of semicolons instead of commas. Korean punctuation uses both commas and interpuncts for lists. Parentheses are usually marked off by round or square brackets, dashes, or commas. In this way any duration can be indicated using a series of semicolons and commas. Punctuation marks were reworked to make the dots and commas heavier. Separators include the space character and commas and semi-colons followed by a space. He also was fond of dashes and colons, where modern editions use commas. Newlines, commas, and other characters can cause delimiter collisions. An example of recursive grammar is a clause within a sentence separated by two commas. Essential clauses are not set off with commas; nonessential clauses are. As well as specify multiple specific time intervals with commas (1,2,3,etc.. These numbers are divided by periods, commas, or blank spaces. Digit groups are not separated by commas, periods, or spaces. Multiple changes can be specified by separating multiple symbolic modes with commas (without spaces).