(1) In this section, "teacher" has the meaning given under s. 40.02(55), but excludes the superintendent of schools, deputy superintendent of schools, associate superintendent of schools, executive assistant to the superintendent of schools, assistant to the superintendent of schools, assistant superintendent, division director and department director.(1m) The appointment of a teacher in a 1st class city school district shall be probationary. After successful probation by completing 3 years of continuous service, the appointment shall be permanent during efficiency and good behavior. A teacher who has a permanent appointment shall not be discharged, except for cause upon written charges. After 10 days' written notice to the teacher of the charges and upon the teacher's written request, the charges shall be investigated, heard and determined by the board. The action of the board on the matter shall be final.(2) Any teacher employed in a public school in territory annexed to the city, who at the time of the annexation possesses the qualifications required by law and by the rules of the board for probationary or permanent appointment to a teaching position in the city, shall have the status of a regularly appointed teacher in the schools of the city and shall be entitled to all the rights and privileges of regularly appointed teachers in the city. Time spent in teaching in the annexed territory prior to annexation shall be credited to each such teacher as time spent in teaching in the city.(3) This section does not apply after December 21, 1995. Any person whose employment is permanent under this section on December 21, 1995, shall retain all of the rights and privileges of such permanent employment after that date.1981 c. 96 s. 67; 1985 a. 225; 1989 a. 4; 1991 a. 39; 1993 a. 58; 1995 a. 111. Teacher tenure laws are in derogation of the common law, creating a contract between the parties by operation of law, and therefore are to be strictly construed. The scope of the tenure created by the statute, or by school board rule enacted pursuant to statute, must be determined from the language of the section and cannot be broadened beyond the intent of the legislature. Farley v. Milwaukee Board of School Directors, 49 Wis. 2d 765, 183 N.W.2d 148 (1971). A probationer gains permanent status upon completion of six semesters; the school board's letter, sent after the sixth semester stating the plaintiff would not be reappointed, was ineffective. Bufkin v. Milwaukee Board of School Directors, 179 Wis. 2d 228, 507 N.W.2d 571 (Ct. App. 1993).