There shall be NONE third party link nor ANY search box by default, simply because of what you buy shall stay intact in the first place. And options can be given to user to decide to include a search box, links to TELNIC and so on.
Finally, registration contract was not with TELNIC, but with registrar, and TELNIC is still third party to domain name holder, and by the agreement TELNIC has no rights to place third party content, as that would be abuse of the paid service. TEL domain is not Geocities, Netfirms or some other free services, where user displays advertising of the Geocities and in exchange get his website.
On their forum telname.com/forum, they certainly were giving incentives or approvals for commercial directories, but "forgot" to mention on their website, that it is impossible to build such, and that such dark stuff lies in their legal agreement when purchasing domain from a registrar. Finally, who reads those legal agreements?
And on TEL domain, in particular, TEL is very much purchased for the purpose of building a commercial directory, including links, phone numbers and addresses. If you browse TEL domains you will see there are so many people with intention to build commercial directories. They can be simply suspended by the sole decision of TELNIC, registrar or agents, etc. But who will gonna have express consent, which means in writing or e-mail, recorded, of all the 3,000 or tens of thousands businesses which some people are advertising on TEL domains.
In case, you place inaccurate information, on your TEL, they have rights to contact you and ask you for correction. A right too much.
In case, you place third party contact information, such as casino phone number, taxi phone number, someone could complain, and they could suspend your service, who knows, maybe even delete your domain. A right too much.
Placing links, contact information about businesses which are anyway else publicly registered, is not illegal in many countries. And no hosting provider would complain to you.
Imagine directories like Yahoo, Anywho.Com, DMOZ and others, to be subject to such rules, to have express permission of those parties.
By that agreement that relates to links, e-mail, any contact information. So by placing a link on your TEL domain to third party, without their express consent and without giving notice to the third party, you are making breach of the agreement and you become subject of their scrutiny, if they wish so.
And from TEL domains, I have many many benefits, except that I don't know what to do, as I have started placing third parties and their contact information, but it is obviously not approved by the agreement, unless I send to them all the notices and get their express permission.