This is the 4023rd most frequent Japanese word.
ドコモ
"ドコモ" (Docomo) is the name of a major Japanese mobile network operator.
Here, 'ドコモ' refers to the Japanese telecommunications company, used to imply the specific brand of phone the speaker uses.
私はドコモの携帯を使っています。
I use a DoCoMo mobile phone.
In this instance, 'ドコモ' identifies a specific brand shop associated with the telecommunications company.
ドコモショップで料金プランを変更しました。
I changed my payment plan at the DoCoMo shop.
The word 'ドコモ' in this sentence describes the service offerings of the company, highlighting the brand name as a descriptor of service quality.