From Longman Dictionary of Contemporary Englishpencil somebody/something ↔ in phrasal verbARRANGE A MEETING, EVENT ETCto make an arrangement for a meeting or other event, knowing that it might have to be changed later Pickford has been pencilled in as Robson’s replacement. → pencil→ See Verb table
Examples from the Corpus
pencil in• Does he have to work hard to control the pencil?• There were boxes of coloured crayons and wax, lead pencils and paints in colours he never knew existed.• Use colored pencils to fill in each section.• The pencils are sold in hardware and building supply stores.• Tweed was watching him closely, pencil gripped in his hand but motionless.• Until he was 70 he drew in pencil and in pen and wash with great neatness.• Place five in the pencil pot in the kitchen.• Why on the sturdy stem of farmers and merchants should one girl blossom into a story-teller in pencil and in words? 