Yang divided diaries of famous leaders into two types: one that was written for a wider audience to read (and, he argued, was therefore not very useful for historians), and another type, which was primarily intended for the writer’s use (he used the phrase “主要是給自己看”) and one in which historians would be able to glimpse the writer’s “內心世界”. Chiang’s was of the second type, according to Yang.

Prof. Yang also commented that when Chiang was asked about his experience of the Xi’an Incident, he replied something to the effect of “you’ll have to wait to read about it in my diary.” So…

BTW, up to this point only the diaries before 1945 are currently available for reading, and only in the form of use copies. And, as the Hoover Institution’s website says,

Given the uninhibited nature of many personal comments in the diaries, family members have chosen to keep some passages private and have thus redacted these from the use copies. Although in most cases the individuals named are deceased, family members wish to protect the feelings of living descendants or other relatives. Recognizing the historical significance of the diaries in their entirety, however, family members have authorized that the redacted passages be released in 2035.