This table contains rules of what category of ticket to exchange to what new category by use of a coupon.
| Column Name | Type | Properties | Docu |
| ruleid | seq64 | Primary-Key | Simple counter key. |
| couponid | string:32 | Foreign-Key=coupon(couponid) | |
| fromcategory | int32 | Foreign-Key=pricecategory(pricecategoryid) | from what category of ticket... |
| tocategory | int32 | Foreign-Key=pricecategory(pricecategoryid) | ..to change to what category of ticket. |
| maxuse | int32 | NULL-able | how often this rule can be used in one order or NULL for unlimited |
| needcategory | int32 | NULL-able Foreign-Key=pricecategory(pricecategoryid) | after the change tickets of this category must exist or NULL if there is no requirement |
| needtickets | int32 | NULL-able | after the change this many tickets of "needcategory" must exist or NULL if there is no requirement; e.g. a Two-for-One rule would change fromcategory="paid" to tocategory="free" if needcategory="paid" still has needtickets="1" ticket |