Meanings behind my Twitter lists

At my Twitter page, you would notice that I have created lists of grouping people. If you look at it, you might not understand what they mean. Here are the lists:

• kagakugijutsu (科学技術): Science and Technology
  
• t1-: People from the United States of America and Canada.
• t4-: People from Europe, including the United Kingdom
• t5-: People from Latin America, including Mexico
  
• t6-: People from Southeast Asia, Australia, and New Zealand
• t27: People from South Africa
  
• t81: People from Japan
• em2a: People who talk about Anime. The name is spelt backwards, with the "ni" (に) changed to "2"
  
• podcast: Owns podcasts that I follow.
• crs-gmi: Backward spelling of "img src" (image source). Owns sites with interesting info that I regularly visit, not necessarily images.
  

Do note that I have listed some of the people in more than one lists, or have yet to list, with the latter being overlooked or having a hard time deciding where to put them in.

PS. The layouts of the anime blogs has changed again, but with both English and Japanese version having completely different themes. The former is based on the technology blog, but using the background and colour scheme of the previous, while the latter was unchanged, but changed the background, font and with minor changes to the colour scheme.