1) Put the following javascript in a tiddler (e.g., [[ConfigTweaks]])
config.views.editor.tagPrompt="whatever you want";
2) Tag this tiddler with "systemConfig"
3) Save and reload your document.
During startup, the tiddler is invoked as a "plugin" (that's what the
"systemConfig" tag means), and the line of javascript is performed,
setting the tagPrompt value to "whatever you want".
Then, when a tiddler editor is displayed, the macro="message ..." in
the [[EditTemplate]] uses the value that was assigned by the
ConfigTweaks plugin.
HTH,
-e
Eric Shulman
TiddlyTools / ELS Design Studios