Code maps are a suite of code spaces that allow receivers to detect tags. A code space is the specific encoding that the tag uses to generate an ID code (and in cases where sensor tags are used, transmit data). Since receivers can be used to detect multiple different tag types they need a code map to allow them to decode the acoustic signals from various tags. This is relevant if you use a mix of ID tags and sensor tags simultaneously or use different models of tags for different species etc.

Since code maps change frequently or are specific to certain regions it is important to check whether the code space used by the tag is compatible with the code map on the receiver and upgrade/downgrade the map accordingly. This vemco page gives a good rundown of 69 kHz maps and compatibility with code spaces. https://www.vemco.com/receiver-code-maps-for-vemco-69-khz-receivers/

Map 414 is one of the newest 180 kHz maps, so far there aren't any obsolete code spaces so you should be ok with any 180 kHz tag. I'd double check though.