亦久亦旧Ao久而旧之Ao
[yì jiŭ yì jiù ao jiŭ ér jiù zhī ao]
It's likely meant to convey 'also old yet enduring', suggesting something timeless and classic ('Ao' seems to be just an emphasized expression). It might represent qualities cherished by the user such as age-old wisdom passed down through time but remains fresh and meaningful.