how to make sub-topics?

[iShift]

Like zero search http://127.0.0.1:43110/Talk.ZeroNetwork.bit/?Topics:5_1PNyuY1iZqXBpft4ArouqcnE4pNRGYij5i/ZeroSearch+bit+sub+topic

[HelloZeroNet]

You have to edit your account's data.json and add type: "group" to the topic you want to turn into a group. eg.:

...
    {
      "body": "Articles about Bitcoin, Torrent and Peer To Peer networks", 
      "added": 1436262090, 
      "type": "group", 
      "topic_id": 1, 
      "title": "P2P news flow"
    }, 
...

http://127.0.0.1:43110/Talk.ZeroNetwork.bit/data/users/1KbV1e1u6P6AsY8XNBydgtbtN8iSB5WMyG/data.json

[iShift]

hmm looks like bug, all users can make groups?

[HelloZeroNet]

Sure, why not, if you dont like it you can delete any time

[iShift]

hm, you mean that i can delete topic belong to another zero user?

[HelloZeroNet]

Yes, the site owner able to delete/modify anything

[iShift]

And how i can publish this change ?

[HelloZeroNet]

Using the sidebar change the content.json to data/users/useraddress/content.json then sign/publish (there was a bug related to this, so updating to latest rev is recommended)