c/f是carried forward的缩写，Cambridge Dictionary给出的解释是：the practice of treating a company’s present profit or loss as if it happened in a later period，中文译为“结转下期”。比如，loss c/f表示“结转至下期损失”，balance c/f表示“结转至下期余额”。

b/f是brought forward的缩写，Cambridge Dictionary给出的解释是：to copy a number from the bottom of a page or column to the top of the next one，中文译为“结转上期”。比如，loss b/f表示“结转至上期损失”，balance b/f表示“结转至上期余额”。