From ConTeXt wiki
|tolerance||verystrict strict tolerant verytolerant stretch|
|align||yes no text|
|blank||fixed halfline line flexible big medium small|
n: number of columns, default is n=2 rule: draw a line between the columns, default is off tolerance: affects spacing, narrow columns should be set tolerant, verytolerant or stretch distance: gap between the columns balance: should the columns be balanced, i.e. should they get the same number of lines? align: left, right (raggedleft, raggedright) blank: amount of whitespace between paragraphs set in columns. Also accepts a dimension as an argument. Column equivalent of \setupwhitespace option: with option=background you can use everything that \setupframed offers direction: default is right, i.e. the first column is on the left; 'left' means the first column is the rightmost. height: ? ntop: ?
Consider using paragraphs or column sets instead of "simple" columns.
ntop has to do with balancing, but I can't make sense of it. See page-mult.tex / minbalancetoplines. height is unclear to me