SINGAPORE – During the making of The Straits Times × National Library Board (NLB) Crossword, a new Singapore-themed crossword series, a surprisingly divisive question surfaced among contributors: Should sardine puffs count as curry puffs?

For some members of the group, sardine puffs were simply another flavour of the familiar local snack, while others insisted they were entirely different foods altogether.

The disagreement shaped how one crossword clue was written and became a small but telling example of the level of discussion, nuance and detail involved in deciding what makes a clue feel “Singaporean”.

The new weekly crossword series, which launches on May 31, grew out of a collaboration involving more than 40 volunteers from both organisations – ranging from junior staff to editors to senior office holders.

Rather than assigning responsibilities according to hierarchy or organisation, contributors signed up for different roles based on interest and skill – with some focusing on clue writing, others constructing crossword grids and the rest dedicated to play-testing the puzzles.

“We don’t necessarily need everybody to be an experienced crossword-setter,” said Ms Rei Kurohi, assistant editor of ST’s newsroom strategy team, adding that the project welcomes anyone who enjoys puzzles, wordplay or simply “making fun things”, and they need not be Singaporean.

But while creating a crossword series sounded straightforward initially, contributors realised that building a puzzle involved far more than simply inserting Singaporean words into a grid.

A clue needed to feel fair – the answer needed to be recognisable without being too obvious.

References had to feel culturally specific without becoming so nic...