"We are conscious of not bastardising the jersey and the black and white stripes, and we want to make the jersey special to those who have it," he said.
Charity applications close on February 11 at 5pm, and a decision on which to support will be made in discussions among union staff, team management and players, and jersey and major sponsor Total Oil.
"It does need to be a local charity, in terms of the need and the timing," Somerville said.
The 2020 choice reflected the needs of farmers and families amid a worsening drought, and last year's choice reflected increasing poverty among families - the two in combination becoming synonymous with a new era of major victories for the Magpies.
Showing their support, players last year helped with packaging and distribution at Nourished for Nil.
The complexities of the Covid crisis mean match schedules can't be confirmed yet, but some unions are getting in early in the hope of Ranfurly Shield challenges against Hawke's Bay.
Hawke's Bay has to allocate challenges to its expected five Bunnings NPC home premier division opponents and to the 2021 winner of the Heartland amateur championship division.
But HBRU chief executive Jay Campbell said eight of the 12 Heartland union teams have applied for challenges.
"Everyone wants to have a crack," he said. "We'll sit down soon and sort it out."
Hawke's Bay has had nine successful defences since winning the Shield off Otago in Dunedin in October 2020, and is now the third-most successful union in the Log o' Wood's 118 years.