sed selective data parsing

i have file in the following format
*RECORD*
FIELD NO
123456
FIELD TX
this is a sample entry
FIELD SA
See Also
FIELD RF
References
FIELD CS
Clinical Symptoms
FIELD AV
Allelic Variants
FIELD EH
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*RECORD*
FIELD NO
123456
FIELD TX
this is a sample entry
FIELD RF
There is no "SA" field, just References
FIELD CS
Clinical Symptoms. There are no allelic variants (AV) field
FIELD EH
Edit History

1) How to parse this data using SED?
2) Extract field, if available

Any input if available

No duplicate or cross-posting, read the rules.

Proceed here: sed/awk script selective insert between lines

Thread closed.