```bitbake
SUMMMARY = "PLOS Base System"
LICENSE = "MIT"
PR = "r1"

inherit packagegroup

# For backwards compatibility after rename
RPROVIDES_packagegroup-base-plos = "packagegroup-plos-base"
RREPLACES_packagegroup-base-plos = "packagegroup-plos-base"
RCONFLICTS_packagegroup-base-plos = "packagegroup-plos-base"

RDEPENDS_${PN} = " \
    formfactor \
    timestamp-service \
    matchbox-wm \
    plos-x-session \
    pointercal-xinput \
    apache2 \
    webmin \
    firefox \
"
```

Remove match-box and firefox packages
user
```bitbake
SUMMMARY = "PLOS Base System"
LICENSE = "MIT"
PR = "r1"

inherit packagegroup

# For backwards compatibility after rename
RPROVIDES_packagegroup-base-plos = "packagegroup-plos-base"
RREPLACES_packagegroup-base-plos = "packagegroup-plos-base"
RCONFLICTS_packagegroup-base-plos = "packagegroup-plos-base"

RDEPENDS_${PN} = " \
    formfactor \
    timestamp-service \
    plos-x-session \
    pointercal-xinput \
    apache2 \
    webmin \
"
```
assistant