Keywords are sometimes used to organize mail files. The purpose in placing them into a message is to allow searching a mail file by topic. In MM, a command like headers keyword bird would find all messages with the keyword bird in them, for example. The person sending the message may place the keyword there, or the person receiving the message can insert the keyword.
Keywords appear in a header field labelled Keywords.
The command keyword adds one or more keywords to a message. Type keyword followed by the keyword. In this example, a display headers command is used to see the result.
S>keyword meeting S>d h From: Joseph Brennan <jb51@cunixf.cc.columbia.edu> To: fb2 Cc: mm33, hk12 Subject: Meeting on Sept 21 Keywords: meeting
If you enter another keyword command, like keyword bird, the addtional keyword is added, so the keywords field would read Keywords: meeting, bird.
To change your mind and remove a keyword, type unkeyword and the keyword. You also have an option to type unkeyword * to remove all keywords from the message. When the last keyword is removed, the Keyword header field is removed from the message.
Your correspondents may include keywords in their messages, or you can add them yourself to messages you have received. Obviously a search like headers keyword bird will bring up all related messages only if all the messages really have the keyword bird in them.
You can use the command keyword to add keywords to messages in your mail file. At the MM> prompt, it refers to the current message unless you specify a message-sequence; at the R> prompt it refers to the message you just read. The unkeyword command functions similarly to remove keywords.
MM>keyword bird 6
R>keyword bird
When you use the headers command, you will see a K at the left of any messages with a keyword. When you read the message, you can see the Keyword header field.
If you use keywords regularly, you may want to store them in a variable called keywords so that you can use the TAB key to save typing. For example, suppose you use ornithology as a keyword. First, store it in the variable by typing set keywords ornithology and then save-init.
MM>set keywords ornithology MM>save-init
Now, to place the keyword in the message, type just the beginning of the keyword and press the TAB key, and the word will be completed for you. In the example, since only one keyword begins with o, only the one letter o was needed.
S>keyword ornithology
To make any change to the keyword variable, you have to retype the list of words. For example, to add entomology you have to type out set keywords ornithology, entomology, and then save-init. To eliminate everything, type set keywords with no words after it, and then save-init.
It is common enough to avoid use of keywords by agreeing to put certain words in the subject field of messages. (You can change the subject field of received messages with the edit command to get the chosen word into the field.) You can then use the message sequence subject to locate messages on a topic just as you would use keyword. Use of the message sequence text may also substitute for use of keywords.