Android armeabi devices with API level 15+

Android itself doesn't support ARM versions below ARMv7 from Android 4.4 (API level 19). Since Android 4.0 (API level 15), it doesn't support ARMv5/ARMv6 by default but can be modified to build for those platforms (see https://groups.google.com/d/msg/android-building/Q_gU1zb6DLc/Bq5QryioQ_kJ), and there are custom builds that run on ARMv6. I'm not entirely sure if there are any official, certified compatible devices that run such a combination (Android 4.0-4.3) though - there should at least not be any such certified devices running Android 4.4, since the compatibility definition document strictly requires ARMv7 from that version.

So in practice you should be pretty safe to skip it, but you might exclude some fringe third party ROMs by doing that.

See https://stackoverflow.com/a/28926267/3115956 for a similar answer to a similar question.