Certification from the National Board of Professional Teaching Standards (NBPTS) offers experienced teachers opportunities through a written portfolio to "match" their practice to the Board's standards. In creating standards and requiring teachers to argue in writing that they have realized the standards in their teaching the NBPTS may offer a national discourse about teaching and as such may form a "discourse community." However since teachers' working knowledge is local, contextualized, personal, and oral, teachers may find difficulties in entering such a discourse. Using interviews and qualitative analysis, this study of four teachers applying for NBPTS certification found that teachers have difficulty representing their knowledge about practice in writing. Those candidates who were most successful were able to assume the NBPTS discourse values which may be at odds with teachers' "working knowledge."