README: document supported.patchlevels

README.md

@@ -20,6 +20,7 @@ device.name1=maguro
 device.name2=toro
 device.name3=toroplus
 supported.versions=6.0 - 7.1.2
+supported.patchlevels=2019-07 -
 
 block=/dev/block/platform/omap/omap_hsmmc.0/by-name/boot;
 is_slot_device=0;
@@ -36,6 +37,8 @@ __do.cleanuponabort=0__ will keep the zip from removing it's working directory i
 
 __supported.versions=__ will match against ro.build.version.release from the current ROM's build.prop. It can be set to a list or range. As a list of one or more entries, e.g. `7.1.2` or `8.1.0, 9` it will look for exact matches, as a range, e.g. `7.1.2 - 9` it will check to make sure the current version falls within those limits. Whitespace optional, and supplied version values should be in the same number format they are in the build.prop value for that Android version.
 
+__supported.patchlevels=__ will match against ro.build.version.security_patch from the current ROM's build.prop. It can be set as a closed or open-ended range of dates in the format YYYY-MM, whitespace optional, e.g. `2019-04 - 2019-06`, `2019-04 -` or `- 2019-06` where the last two examples show setting a minimum and maximum, respectively.
+
 `block=auto` instead of a direct block filepath enables detection of the device boot partition for use with broad, device non-specific zips. Also accepts specifically `boot` or `recovery`.
 
 `is_slot_device=1` enables detection of the suffix for the active boot partition on slot-based devices and will add this to the end of the supplied `block=` path. Also accepts `auto` for use with broad, device non-specific zips.