LoA validation is one of the validation types when adding the IP resources to the Heficed's IP Address Market.
In case you still see validation pending for the LoA authorization that means that you most likely did not submit your LoA yet. To do that, please send the LoA issued by the owner of the IP resources (as seen in WHOIS) to firstname.lastname@example.org.
Please use this subject pattern: "LoA validation: subnet X.X.X.X/YY", where X.X.X.X/YY is the subnet in CIDR notation.
Furthermore, please note that after the submission of the LoA, you (or the company contact provided in the LoA) might be contacted to confirm the validity of the LoA.