+After getting the results, you can untick various trades individually,
+and select `Update' to get a new plan. The unticked trades will be
+excluded from the voyage plan (if any) and also from the totals.
+
+<h3>Vessel capacity</h3>
+
+If you don't specify a vessel or a vessel capacity, the trading plan
+will not take into account the fact that your voyage will be on a ship
+with a limited size. This will probably result in a plan
+which trades excessively cumbersome goods (eg. hemp, wood, iron).
+
+<p>
+
+So you should specify your vessel capacity. You can enter things
+like:
+<dl>
+<dt>sloop
+<dd>The capacity of a sloop, leaving no allowance for rum and shot
+<dt>wb - 1%
+<dd>The capacity of a war brig minus 1%
+<dt>20t 13kl
+<dd>13 tonnes (13,000kg), 20 kilolitres (20,000l)
+<dt>sloop - 100l 100kg
+<dd>The capacity of a sloop minus 100l, minus 100kg
+<dt>2t plus 500kg minus 200kg
+<dd>2300kg, with no limit on volume
+</dl>
+Evaluation is strictly from left to right.
+
+<p>
+
+Formally, the capacity is a list of terms, all but the first preceded
+by one of <kbd>-</kbd>, <kbd>minus</kbd>, <kbd>+</kbd>,
+<kbd>plus</kbd>. Each term may specify a mass and/or a volume
+(separated by a space), as a number followed (without an intervening
+space) by a unit (<kbd>t</kbd>, <kbd>kg</kbd>, <kbd>kl</kbd> or
+<kbd>l</kbd>). Alternatively each term except the first may specify a
+percentage, which is applied as a percentage change to the answer from
+all the preceding terms. The first term may be a ship name or
+abbrevation instead. If the first term specifies only one of mass or
+volume, all the subsequent terms may only adjust that same value.
+
+<h3>Expected losses</h3>
+
+In theory if you were guaranteed to have a trouble-free voyage it
+would be worth trading goods at very low margins. However, in
+practice problems can arise: you may be attacked and lose your stock,
+or market conditions may change between your collection and delivery
+of the goods.
+
+<p>
+
+We model this by pretending that you expect to lose a fixed proportion
+of your stock each league you sail. This expected loss does not
+appear in the trade tables (although the distance does), but it does
+affect the way the voyage trading plan optimiser chooses which trades
+to do.
+
+<p>
+
+Trades whose margin is less than the expected loss are never included
+in the suggested plan. For example, if you select 1% loss per league,
+and plan a voyage of 5 leagues, then any trade with a margin of less
+than 5.15% would be completely excluded (5.15% not 5% because the loss
+works like compound interest). Theoretically very profitable trades
+which are close to the expected break-even point because of the
+distance can also be rejected by the optimiser in favour of shorter
+distance trades with theoretically smaller margins, if it's not
+possible to do both.
+
+<p>
+
+As a guide: you may expect to lose between 0.1% and 1% per league.
+0.1% would correspond, for example, to losing one fight to brigands
+every ten 10-league voyages.
+
+<p>