Meaning of the YRIMMIG value 1990 (1990 pums: 1987-1990) in 2000 5% US Census

I am working with 2000 (5%) US Census data and interested in finding those who entered the US a decade ago i.e., 1990.

Tabulating the variable “YRIMMIG” gives a value “1990 (1990 pums: 1987-1990)”. What does this mean (especially 1990 pums: 1987-1990)?

Should I select those with YRIMMIG equal to 1990 or would it overstate?

As noted on the YRIMMIG description tab “[f]or the 2000 census…exact years are reported back to 1935; some years prior to 1935 are collapsed into categories.” The label for the 1990 code is specific to the 1990 PUMS file; in the 1790-1990 census, respondents were asked to report the range of years that included their year of arrival. The label you are describing is intended to denote that in the 1990 PUMS a code of 1990 represents arrival anytime between 1987 and 1990.