Mine

OS := $(shell dpkg-architecture -qDEB_HOST_ARCH_OS)
ARCH := $(shell dpkg-architecture -qDEB_HOST_ARCH)
DIST := $(shell lsb_release -is)
DISTREL := $(shell lsb_release -cs)
# Figure out who's building this package.
OOO_VENDOR:=Debian

...
[CUT]
...

ifeq "$(DIST)" "Ubuntu"
  # common settings
  PATCHSET=$(DIST)$(shell perl -e 'print ucfirst("$(DISTREL)");')
  CONFIGURE_FLAGS += \
       --with-intro-bitmaps=$(CURDIR)/ubuntu/openintro_ubuntu.bmp \
       --with-about-bitmaps=$(CURDIR)/ubuntu/openabout_ubuntu.bmp

  BUILD_DEPS += , translate-toolkit
  
  HUMAN=human
  IMAGES_HUMAN_ZIP=images_human.zip