Case study
1. Credit promisor
According to the Uniform rules for collection, it says a bank agrees to pay. (Refer to the 2 of U.C.P.).Therefore, unlike a bank, a general company can not be a promisor of credit. Although it used a word 'Credit', it is not a credit but a written guarantee. As a result, the Guarantee issued by the headquarter is a mere Guarantee and not a stand by L/C.

2. The title of credit
There is no need to use a term 'Credit' to process L/C. And you may use 'Documentary payment order" term. You don't need to use term 'documentary' even though you are using the term 'credit' It is acceptable to use just "Letter of Credit. (I.C.C. pub 459. Case No.3)

3. A definite promise of payment
I means a agreement of a payment, undertaking purchasing and usance if a document meets all the condition for the credit. As long as such payment agreement is made by a bank, it can be regarded as a credit of U.C.P.

Cautions
A credit must be Banking Letter of Credit issued by a bank. But at this point, the definition for a bank is not clear. Moreover, a credit from some foreign countries are sometimes issued by an organization that does not have a banking mechanism. Also, a definition for a bank is different from each country therefore, the domestic general merchant banks should be also included in the category of a financial agency. Since the details for a bank or a financial agency are diverse in each country, you will need to find out whether a bank is apt to issue a credit through referring to the Banking Directory.
Given that fact, you should take into consideration when dealing with a credit issued by a bank that doesn't have a correspondent agreement because there is no way to confirm the presence of authenticity against the credit.