An rc style file can be created for CASA that allows the user to specify default settings. There are several names that are accepted for the rc file that must appear in your home directory:
    ~/.casarc
    ~/.casa/rc
    ~/.aipsrc

and there are several that are accepted as part of the AIPS structure:
    $AIPSROOT/.aipsrc
    $AIPSHOST/aipsrc
    $AIPSSITE/aipsrc
    $AIPSARCH/aipsrc

These are consulted in the given order until a match is found. The form of an entry is "keyword: value" and some of the most commonly used are:
    userinfo.name
        example:    userinfo.name: John.Doe

    userinfo.email
        example:    userinfo.email: jdoe@lame.example

    userinfo.org
        example:    userinfo.org: NRAO

    display.axislabels
        example:    display.axislabels: on

    display.colormaps.defaultcolormap
        example:    display.colormaps.defaultcolormap: Greyscale 1

    display.axislabels.charsize
        example:    display.axislabels.charsize: 1.2

    display.controls.linewidth
        example:    display.controls.linewidth: 2

    viewer.colorscheme
        example    viewer.colorscheme: paper

    display.axislabels.linewidth
        example    display.axislabels.linewidth: 2.1

Additional examples can be found at http://casa.nrao.edu/docs/userman/UserManse78.html and more parameters will be exposed and documented in a future CASA release.