BT Décor 2600 Telephone with Call Guardian and Answering Machine BT Decor 2600 Advanced Call Blocker – block up to 100% of nuisance calls. The BT Decor 2600 can block up to 1000 individual numbers, meaning that you really can avoid speaking to the people you don’t want to. Over time, the phone learns which calls you do and don’t want to take. The BT Décor 2600 Advanced Call Blocker, powered by TrueCall’s award winning technology, offers users complete control over which calls they want to take and those they wish to block. Call Guardian. The BT Décor 2600 includes BT’s Call Guardian, which means you’ll never have to speak to another cold caller again: Call Guardian screens incoming calls: Numbers on your contact list get straight through to numbers you have blocked are rejected (selected by user). For all other calls. Call Guardian asks the caller to say their name and then asks the user whether they want to accept or block the call without speaking to the caller. Blocking calls can be done in a number of ways: Block by Number (or Area Code). Send Calls to the Answer Phone. If you are unsure if you want to block the call, you can send them to the answer phone and then Block from your calls list later.