The nouns which MUD accepts are arranged in a hierarchy of "classes". For example, in the cottage there is a 'groat'. The groat is a kind of 'coin', and all coins are a kind of 'money'. Money is a subclass of 'treasure', which in turn is one kind of 'solid'. All solids (and everything else, for that matter) are of class 'object', also known as 'all'.

Now, if you were in a room and said G GROAT, it would only pick up the groat. G COIN would pick up the groat and any other coins there, and G MONEY would pick up all objects of type money (which of course includes the groat). G TREASURE (shortened to G T) will pick up anything in the room which is worth points, and G SOLID will get anything solid (treasure or not). G ALL will attempt to get everything in the room.

This classification system works with nearly all commands in MUD, although the fancier aspects of it aren't used so often. So long as you remember G T, G ALL, DR T and DR ALL, you should get along fine.