Frost Comparative Migration Studies (2024) 12:23 that examines ambiguities in migration and citizenship policies that could include lawregulation gaps but do not focus on them (Lori, 2019; Natter, 2021; Norman, 2020; Shevel, 2011; Stel, 2020). Thus, this paper asks: How can we conceptualize gaps between laws and their implementing measures? The paper responds to this question by focusing on the content of domestic laws versus the content of related implementing measures, including regulations, instructions, decisions, and decrees. Discrepancies between these two levels of legal rules can provide a clear manifestation of an implementation gap. I conceptualize this law-regulation divergence as intentional ambiguity because the gap occurs with the full knowledge of state officials. Specifically, the term intentional reflects that policymakers are aware that the subsidiary legislation diverges from the law; it is not a gap that occurs without their knowledge because the gap forms at high-levels of governance (not the street-level).4 The next sections elaborate the concept of intentional ambiguity as a type of implementation gap. Then, the paper describes empirical cases of intentional ambiguity by focusing on discrepancies between Jordan’s nationality and passports laws and their related regulations—particularly on policies governing Gaza refugees’ access to passports as well as investors’ and Palestinian-Jordanians’ access to nationality. In each case, senior officials write implementation orders that diverge from the provisions in corresponding laws, producing intentionally ambiguous policies. Comparing different groups of Palestinians, including those with and without Jordanian nationality, is fruitful for illuminating law-regulation implementation gaps. It also expands existing studies, which tend to analyze Palestinian-Jordanians (Brand, 1988; Massad, 2001) separately from Gaza refugees (El-Abed, 2005; Pérez, 2011) or compare the Palestinian-Jordanians to “native” East Bank Jordanians (Abu Odeh, 1999; Brand, 1995). This reflects a tendency to divide groups based on whether they have legal citizen status (i.e., nationality) and to treat a state’s relations with its citizens as largely distinct from its relations with noncitizens. The case on investors’ access to nationality contributes to pushing past this divide, and it highlights how intentional ambiguity can impact more privileged groups. Altogether, these cases exemplify intentional ambiguity. They highlight that it can partially exclude or include a group through regulations that deviate from the law and that these gaps can occur with noncitizens and citizens, with more or less vulnerable groups, as well as in different time periods. In addition, they are cases that allow us to explore intentional ambiguity in an authoritarian and “developing” context, where it is relatively more difficult to identify subsidiary legislation. The availability of data reflects both how long-standing these cases of intentional ambiguity are, making them more legible to researchers, as well as my long-term research on citizenship in Jordan. Since 2016, I have been collecting three main original data sources to study law-regulation gaps. First, archival files from the British National Archives at Kew and the U.S. National Archives at College Park on Jordan’s internal politics from 1946 to 93 to gain an understanding of the circumstances surrounding the adoption of individual policies. Second, 240 interviews I conducted in Jordan with 165 different individuals, including 35 unique current and former ministers,5 during 16 months of fieldwork in Jordan 4 5 In other work, I focus on elaborating how and why intentional ambiguity can occur. These ministers primarily include former prime ministers, ministers of foreign affairs, and ministers of interior. Page 3 of 18