Gracia Imperial brings her 16-month-old daughter Amira to the Winnipeg Public Library every week. They always find something new.

"There's a wide range to the collection here,” she says. “And every week we find new books that are really interesting.”

The library always seems fresh thanks to librarians who go through the shelves and do a process called “weeding.”

They examine each book and throw out the tomes that no longer meet patrons’ needs, making room for the new titles.

Barbara Bourrier-Lacroix showed CTV Winnipeg the “weeding process,” also known as collections management.

“They have a fun little acronym to help you remember as you’re going through your collection,” she said. “It's MUSTIE.”

M stands for misleading, which includes books that seem factually inaccurate or out of date.

U stands for ugly, which includes worn or damaged copies.

S stands for superseded, referring to titles that can be replaced by newer editions.

T stands for trivial, which includes books that are poorly written or were only popular for a short period of time.

I is for irrelevant to the community.

E stands for elsewhere, meaning the information is available in another format or at another branch.

During a recent round of weeding, Bourrier-Lacroix found a book with a stain on it and marked it as “Ugly.”

“This one’s got water spilled on it,” she said. “We hope it’s water.”

“It’s constant upkeep,” she added. “That’s what we do.”