Looking at the DISCUSS logo on the cover, you will notice that the letters are linked together by chains. From the above examples, you should also notice that DISCUSS numbers transactions from [0001] on. Chains group transactions by subject.
When a user enters a new transaction into a DISCUSS meeting, he or she has the choice of starting a new chain, or adding onto an existing chain. The ``talk'' command will prompt the user for a subject, and will enter the transaction as the start of a new chain. The ``reply'' command takes an already existing transaction, and adds the new transaction onto the old transaction's chain. The subject of this new transaction is formed by prepending ``Re:'' to the old subject. So a transaction chain roughly corresponds to a single conversation.
DISCUSS provides commands that allow you to take advantage of the chaining structure. When DISCUSS prints a transaction, it prints out the ``pref'' (previous reference) and ``nref'' (next reference) of that transaction. These are the previous and next transactions within the chain, respectively. By using these numbers, or taking advantage of the ``pref'' and ``nref'' transaction specifiers, you can travel through the chain. Other chain-related transaction specifiers are ``fref'' and ``lref'', which refer to the beginning and end of the chain.