296 2 VONK ET AL. Comparative Methodology: A Typology of Modes of Protection against Statelessness Individuals can be protected against statelessness in two ways. They can be facilitated in the acquisition of a nationality and thereby become a national of a particular country, and they can be protected by not losing a nationality that is already held. Hence, in order to assess the extent to which states provide ­sufficient protection against statelessness, we need to analyze the rules on both acquisition and loss of citizenship. However, citizenship laws often use different terms for similar rules. Comparing legal provisions on acquisition and loss of citizenship therefore requires a standardization of terms and definitions. The typology of ‘modes of protection against statelessness’ is an analytical grid that outlines, in a systematic way, categories of persons that are at risk of being or becoming stateless and outlines, with reference to the most important international standards, the obligation of states under national law on the acquisition and loss of citizenship. The typology of modes of protection against statelessness follows the logic of a more general typology on ‘modes of acquisition of citizenship’5 and ‘modes of loss of citizenship’6 as previously developed by EUDO Citizenship.7 For each mode of protection against statelessness, the typology defines a precise target group of persons at risk of being or becoming stateless (see Table 1 below). By defining standardized target groups, the typology allows us to compare rules applicable to similar at-risk groups across countries. 5 M Vink, O Vonk and I Honohan (2013). EUDO CITIZENSHIP Database on Modes of Acquisition of Citizenship in Europe. San Domenico di Fiesole: Robert Schuman Centre for Advanced Studies, European University Institute, available at http://www.eudo-citizenship .eu/databases/modes-of-acquisition (last accessed on 3 November 2013). 6 M Vink, O Vonk and I Honohan (2013). EUDO CITIZENSHIP Database on Modes of Loss of Citizenship in Europe. San Domenico di Fiesole: Robert Schuman Centre for Advanced Studies, European University Institute, available at http://www.eudo-citizenship.eu/ databases/modes-of-loss (last accessed on 3 November 2013). 7 The databases on acquisition and loss of citizenship have also been complemented by different comparative studies. See in particular the comparative EUDO Citizenship reports on birthright citizenship and loss of citizenship by GR de Groot and M Vink, available at http:// eudo-citizenship.eu/publications/comparative-analyses, as well as De Groot’s ‘Survey on Rules on Loss of Nationality in International Treaties and Case Law’. The latter paper was prepared in the context of the ILEC (Involuntary Loss of European Citizenship) Project and is available at http://www.ceps.eu/book/survey-rules-loss-nationality-international-treaties -and-case-law (last accessed on 3 November 2013). tilburg law review 19 (2014) 294-302