The numbers in purple color and in parenthesis at the end of your paragraph are called "Purple Numbers."  
They are system generated and show up as something like "{nid 13PL}" when you are in your editing window. 
Just leave them alone, and make sure they stay there (with a space between your text and
the "{nid AAAA}") even when you make amendments to your work (because that will allow people 
to come back to this particular paragraph or this position in the work.)    (13PL)

Purple Numbers allow a finer grain access to web pages. It allows us to link to a specific paragraphs or bullet point inside a web page, rather than merely taking us to the top of that page like url's normally do.    (AMZ)

With Purple numbers in place, all one needs to do is to mouse-over a Purple number, right-mouse-click and COPY that hyperlink (on the IE browser, it's "Copy Shortcut", and on the Netscape browser, it's "Copy Link Location"). One can then PASTE this hyperlink to an e-mail message, to your instant message, or to a document s/he is composing. That link will now take its reader back to exactly the same paragraph the author wanted to refer his/her reader(s) to.    (AN0)

If you are not familiar with Purple numbers you may want to read up on Doug Engelbart's work on OHS and high resolution addressability. See also Eugene Eric Kim's “An Introduction to Purple”, Eric Armstrong's comments on granular addressability, and Matthew Schneider's PurpleSlurple.    (AN1)

Examples:    (13PM)

    (AN2)

Try putting PurpleNumbers on existing web pages with PurpleSlurple at: http://ps1.cim3.net/ps.php (Important: be fully aware, though, that the persistence of purple numbers thus created are dependent on the peristence of the source web page.)    (AN7)

For a little history on Purple Numbers, see: http://community.cim3.net/cgi-bin/wiki.pl?PurpleNumbers#nidAAL    (AN8)