Orzo is a pasta made with wheat. It resembles rice and it is usually OK to substitute rice or quinoa in recipies that call for orzo.
Triticale and bulgar are varieties of wheat. Some people who are on a wheat free diet report that they can tolerate triticale and/or bulgar but they are definitely not gluten free.
As you may know, many of my titles have the format “Is this food gluten free?” This format is ideal for getting the attention of the computers that place articles on google and the other search engines. You may also have noticed that in every case my answer boils down to “Yes if you take certain precautions.” I have added a tag to all articles of this type so that you can find them quickly. To use these tags, scroll down to the end of this article, past the ads. You will will see the words “is this food gluten free?”. Click on the tag and your computer will create a special page containing the first few sentences of each of my articles that have the same tag. Click on the excerpt to read the complete article.